485BPOS

As filed with the Securities and Exchange Commission on
February 13, 2019
Registration No. 33-51017
811-07121
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
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FORM N-1A
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REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	/ X /
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Pre-Effective Amendment No.	/    /
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Post-Effective Amendment No. 42	/ X /
and/or	----
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REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY	/ X /
ACT OF 1940	----
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Amendment No. 43	/ X /
(Check appropriate box or boxes)	----
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PUTNAM ASSET ALLOCATION FUNDS
(Exact name of Registrant as Specified in Charter)
100 Federal Street, Boston, Massachusetts 02110
(Address of Principal Executive Offices) (Zip Code)
Registrant's Telephone Number, including Area Code
(617) 292-1000
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It is proposed that this filing will become effective
	(check appropriate box)
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/    /	immediately upon filing pursuant to paragraph (b)
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/ X /	on January 30, 2019 pursuant to paragraph (b)
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/    /	60 days after filing pursuant to paragraph (a)(1)
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/    /	on (date) pursuant to paragraph (a)(1)
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/    /	75 days after filing pursuant to paragraph (a)(2)
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/    /	on (date) pursuant to paragraph (a)(2) of Rule 485.
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	If appropriate, check the following box:
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/    /	this post-effective amendment designates a new
----	effective date for a previously filed post-effective amendment.
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	ROBERT T. BURNS, Vice President
	PUTNAM ASSET ALLOCATION FUNDS
	100 Federal Street
	Boston, Massachusetts 02110
	(Name and address of agent for service)
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	Copy to:
	BRYAN CHEGWIDDEN, Esquire
	ROPES & GRAY LLP
	1211 Avenue of the Americas
	New York, New York 10036
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PUTNAM ASSET ALLOCATION FUNDS

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act of 1933, as amended, and has duly caused this Amendment to its Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Boston, and The Commonwealth of Massachusetts, on the 13^th day of February, 2019.

Putnam Asset Allocation Funds

By: /s/ Jonathan S. Horwitz,

Executive Vice President, Principal Executive Officer and Compliance Liaison

Pursuant to the requirements of the Securities Act of 1933, as amended, this Amendment to the Registration Statement has been signed below by the following persons in the capacities and on the date indicated:

Signature Title

Kenneth R. Leibler* Chair, Board of Trustees

Robert L. Reynolds* President and Trustee

Jonathan S. Horwitz* Executive Vice President, Principal Executive Officer and Compliance Liaison

Janet C. Smith* Vice President, Principal Financial Officer, Principal Accounting Officer and Assistant Treasurer

Liaquat Ahamed* Trustee

Ravi Akhoury* Trustee

Barbara M. Baumann* Trustee

Katinka Domotorffy* Trustee

Catharine Bond Hill* Trustee

Paul L. Joskow* Trustee

Robert E. Patterson* Trustee

George Putnam, III* Trustee

Manoj P. Singh* Trustee

By: /s/Jonathan S. Horwitz, as Attorney-in-Fact

February 13, 2019

* Signed pursuant to power of attorney filed in Post-

Effective Amendment No. 41 to the Registrant's

Registration Statement on January 25, 2019.

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Putnam Dynamic Asset Allocation Growth Fund

Fund Summary

Goal

Putnam Dynamic Asset Allocation Growth Fund seeks capital appreciation.

Fees and expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Putnam Dynamic Asset Allocation Growth Fund	Class A		Class B		Class C		Class M	Class P	Class R	Class R5	Class R6	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%		none		none		3.50%	none	none	none	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)	1.00%	[1]	5.00%	[2]	1.00%	[3]	none	none	none	none	none	none

Annual fund operating expenses (expenses you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - Putnam Dynamic Asset Allocation Growth Fund	Class A	Class B	Class C	Class M	Class P	Class R	Class R5	Class R6	Class Y
Management fees)	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Distribution and service (12b-1) fees	0.25%	1.00%	1.00%	0.75%		0.50%
Other expenses	0.23%	0.23%	0.23%	0.23%	0.07%	0.23%	0.21%	0.11%	0.23%
Total annual fund operating expenses	1.07%	1.82%	1.82%	1.57%	0.66%	1.32%	0.80%	0.70%	0.82%

Example

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Expense Example - Putnam Dynamic Asset Allocation Growth Fund - USD ($)	Expense Example, with Redemption, 1 Year	Expense Example, with Redemption, 3 Years	Expense Example, with Redemption, 5 Years	Expense Example, with Redemption, 10 Years
Class A	678	896	1,131	1,806
Class B	685	873	1,185	1,940
Class C	285	573	985	2,137
Class M	504	828	1,175	2,152
Class P	67	211	368	822
Class R	134	418	723	1,590
Class R5	82	255	444	990
Class R6	72	224	390	871
Class Y	84	262	455	1,014

Expense Example, No Redemption - Putnam Dynamic Asset Allocation Growth Fund - USD ($)	Expense Example, No Redemption, 1 Year	Expense Example, No Redemption, 3 Years	Expense Example, No Redemption, 5 Years	Expense Example, No Redemption, 10 Years
Class B	185	573	985	1,940
Class C	185	573	985	2,137

Portfolio turnover

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 109%.

Investments, risks, and performance

Investments
The fund is one of three Putnam Dynamic Asset Allocation Funds, each of which has a unique strategic, or typical, allocation between equity and fixed-income investments. Using qualitative analysis and quantitative techniques, we adjust portfolio allocations from time to time within a certain range for each fund to try to optimize a fund’s performance consistent with its goal. The strategic allocation and the range of allowable allocation for the fund are shown below.

Class	Strategic allocation	Range
Equity	80%	65-95%
Fixed Income	20%	5-35%

We invest mainly in equity securities (growth or value stocks or both) of both U.S. and foreign companies of any size. We may consider, among other factors, a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell equity investments. We also invest, to a lesser extent, in fixed-income investments, including U.S. and foreign government obligations, corporate obligations and securitized debt instruments (such as mortgage-backed investments). We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell fixed-income investments. We may also select other investments that do not fall within these asset classes. We typically use to a significant extent derivatives, such as futures, options, certain foreign currency transactions, warrants and swap contracts, for both hedging and non-hedging purposes.

Risks

It is important to understand that you can lose money by investing in the fund.

Our allocation of assets among asset classes may hurt performance. The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and value stocks may fail to rebound. These risks are generally greater for small and midsize companies.

Bond investments are subject to interest rate risk, which means the value of the fund’s bond investments is likely to fall if interest rates rise. Bond investments also are subject to credit risk, which is the risk that the issuer of the bond may default on payment of interest or principal. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (sometimes referred to as “junk bonds”), which may be considered speculative. Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage- and asset-backed investments, in other investments with less attractive terms and yields.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid. Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

Annual total returns for class A shares before sales charges

Best calendar quarter
Q2 2009   19.54%

Worst calendar quarter
Q3 2011 −16.16%

Average annual total returns after sales charges (for periods ended 12/31/18)

Average Annual Total Returns - Putnam Dynamic Asset Allocation Growth Fund		Label	1 Year	5 Years	10 Years
Class A		before taxes	(14.90%)	3.63%	10.14%
Class A | after taxes on distributions			(17.20%)	1.24%	8.54%
Class A | after taxes on distributions and sale of fund shares			(7.86%)	2.32%	7.96%
Class B		before taxes	(14.45%)	3.80%	10.14%
Class C		before taxes	(11.22%)	4.07%	9.96%
Class M		before taxes	(13.29%)	3.60%	9.86%
Class P	[1]	before taxes	(9.30%)	5.21%	11.11%
Class R		before taxes	(9.89%)	4.60%	10.51%
Class R5	[1]	before taxes	(9.41%)	5.15%	11.08%
Class R6	[1]	before taxes	(9.34%)	5.24%	11.15%
Class Y		before taxes	(9.41%)	5.14%	11.07%
Russell 3000 Index (no deduction for fees, expenses or taxes)	[2]		(5.24%)	7.91%	13.18%
Putnam Growth Blended Benchmark (no deduction for fees, expenses or taxes, other than withholding taxes on reinvested dividends in the case of the MSCI EAFE Index (ND))			(5.91%)	5.63%	10.55%

The Putnam Growth Blended Benchmark is an unmanaged index administered by Putnam Management, 60% of which is the Russell 3000 Index, 15% of which is the MSCI EAFE Index (ND), 15% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 5% of which is the JPMorgan Developed High Yield Index and 5% of which is the MSCI Emerging Markets Index (GD).

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

Class B share performance reflects conversion to class A shares after eight years.

[1] Applies only to certain redemptions of shares bought with no initial sales charge.

[2] This charge is phased out over six years.

[3] This charge is eliminated after one year.

[1] Performance for class R5 and class R6 shares prior to their inception (7/2/12) and for class P shares prior to their inception (8/31/16) is derived from the historical performance of class Y shares and has not been adjusted for the lower investor servicing fees applicable to class R5, class R6 and class P shares; had it, returns would have been higher.

[2] Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to the Russell Indexes. Russell(R) is a trademark of Frank Russell Company.

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Putnam Dynamic Asset Allocation Balanced Fund

Fund Summary

Goal

Putnam Dynamic Asset Allocation Balanced Fund seeks total return. Total return is composed of capital appreciation and income.

Fees and expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Putnam Dynamic Asset Allocation Balanced Fund	Class A		Class B		Class C		Class M	Class P	Class R	Class R5	Class R6	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%		none		none		3.50%	none	none	none	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)	1.00%	[1]	5.00%	[2]	1.00%	[3]	none	none	none	none	none	none

Annual fund operating expenses (expenses you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - Putnam Dynamic Asset Allocation Balanced Fund	Class A	Class B	Class C	Class M	Class P	Class R	Class R5	Class R6	Class Y
Management fees)	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%
Distribution and service (12b-1) fees	0.25%	1.00%	1.00%	0.75%		0.50%
Other expenses	0.20%	0.20%	0.20%	0.20%	0.06%	0.20%	0.20%	0.10%	0.20%
Total annual fund operating expenses	0.97%	1.72%	1.72%	1.47%	0.58%	1.22%	0.72%	0.62%	0.72%

Example

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Expense Example - Putnam Dynamic Asset Allocation Balanced Fund - USD ($)	Expense Example, with Redemption, 1 Year	Expense Example, with Redemption, 3 Years	Expense Example, with Redemption, 5 Years	Expense Example, with Redemption, 10 Years
Class A	668	866	1,080	1,696
Class B	675	842	1,133	1,831
Class C	275	542	933	2,030
Class M	494	799	1,125	2,046
Class P	59	186	324	726
Class R	124	387	670	1,477
Class R5	74	230	401	894
Class R6	63	199	346	774
Class Y	74	230	401	894

Expense Example, No Redemption - Putnam Dynamic Asset Allocation Balanced Fund - USD ($)	Expense Example, No Redemption, 1 Year	Expense Example, No Redemption, 3 Years	Expense Example, No Redemption, 5 Years	Expense Example, No Redemption, 10 Years
Class B	175	542	933	1,831
Class C	175	542	933	2,030

Portfolio turnover

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 129%.

Investments, risks, and performance

Investments
The fund is one of three Putnam Dynamic Asset Allocation Funds, each of which has a unique strategic, or typical, allocation between equity and fixed-income investments. Using qualitative analysis and quantitative techniques, we adjust portfolio allocations from time to time within a certain range for each fund to try to optimize a fund’s performance consistent with its goal. The strategic allocation and the range of allowable allocation for the fund are shown below.

Class	Strategic allocation	Range
Equity	60%	45-75%
Fixed Income	40%	25-55%

We invest mainly in equity securities (growth or value stocks or both) of both U.S. and foreign companies of any size. We may consider, among other factors, a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell equity investments. We also invest in fixed-income investments, including U.S. and foreign government obligations, corporate obligations and securitized debt instruments (such as mortgage-backed investments). We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell fixed-income investments. We may also select other investments that do not fall within these asset classes. We typically use to a significant extent derivatives, such as futures, options, certain foreign currency transactions, warrants and swap contracts, for both hedging and non-hedging purposes.

Risks

It is important to understand that you can lose money by investing in the fund.

Our allocation of assets among asset classes may hurt performance. The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and value stocks may fail to rebound. These risks are generally greater for small and midsize companies.

Bond investments are subject to interest rate risk, which means the value of the fund’s bond investments is likely to fall if interest rates rise. Bond investments also are subject to credit risk, which is the risk that the issuer of the bond may default on payment of interest or principal. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (sometimes referred to as “junk bonds”), which may be considered speculative. Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage- and asset-backed investments, in other investments with less attractive terms and yields.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid. Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

Annual total returns for class A shares before sales charges

Best calendar quarter
Q2 2009  16.13%

Worst calendar quarter
Q3 2011   −11.35%

Average annual total returns after sales charges (for periods ended 12/31/18)

Average Annual Total Returns - Putnam Dynamic Asset Allocation Balanced Fund		Label	1 Year	5 Years	10 Years
Class A		before taxes	(12.54%)	3.36%	9.43%
Class A | after taxes on distributions			(14.42%)	1.72%	8.07%
Class A | after taxes on distributions and sale of fund shares			(6.43%)	2.34%	7.37%
Class B		before taxes	(12.19%)	3.48%	9.43%
Class C		before taxes	(8.77%)	3.81%	9.26%
Class M		before taxes	(10.92%)	3.34%	9.14%
Class P	[1]	before taxes	(6.81%)	4.93%	10.40%
Class R		before taxes	(7.43%)	4.32%	9.80%
Class R5	[1]	before taxes	(6.95%)	4.86%	10.37%
Class R6	[1]	before taxes	(6.86%)	4.97%	10.44%
Class Y		before taxes	(6.95%)	4.86%	10.37%
Russell 3000 Index (no deduction for fees, expenses or taxes)	[2]		(5.24%)	7.91%	13.18%
Putnam Balanced Blended Benchmark (no deduction for fees, expenses or taxes, other than withholding taxes on reinvested dividends in the case of the MSCI EAFE Index (ND))			(3.90%)	5.24%	9.22%

The Putnam Balanced Blended Benchmark is an unmanaged index administered by Putnam Management, 50% of which is the Russell 3000 Index, 35% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 10% of which is the MSCI EAFE Index (ND) and 5% of which is the JPMorgan Developed High Yield Index.

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

Class B share performance reflects conversion to class A shares after eight years.

[1] Applies only to certain redemptions of shares bought with no initial sales charge.

[2] This charge is phased out over six years.

[3] This charge is eliminated after one year.

[1] Performance for class R5 and class R6 shares prior to their inception (7/2/12) and for class P shares prior to their inception (8/31/16) is derived from the historical performance of class Y shares and has not been adjusted for the lower investor servicing fees applicable to class R5, class R6 and class P shares; had it, returns would have been higher.

[2] Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to the Russell Indexes. Russell(R) is a trademark of Frank Russell Company.

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Putnam Dynamic Asset Allocation Conservative Fund

Fund Summary

Goal

Putnam Dynamic Asset Allocation Conservative Fund seeks total return consistent with preservation of capital. Total return is composed of capital appreciation and income.

Fees and expenses

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Putnam Dynamic Asset Allocation Conservative Fund	Class A		Class B		Class C		Class M	Class P	Class R	Class R5	Class R6	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%		none		none		3.50%	none	none	none	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)	1.00%	[1]	5.00%	[2]	1.00%	[3]	none	none	none	none	none	none

Annual fund operating expenses (expenses you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - Putnam Dynamic Asset Allocation Conservative Fund	Class A	Class B	Class C	Class M	Class P	Class R	Class R5	Class R6	Class Y
Management fees)	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%	0.52%
Distribution and service (12b-1) fees	0.25%	1.00%	1.00%	0.75%		0.50%
Other expenses	0.22%	0.22%	0.22%	0.22%	0.08%	0.22%	0.19%	0.12%	0.22%
Total annual fund operating expenses	0.99%	1.74%	1.74%	1.49%	0.60%	1.24%	0.71%	0.64%	0.74%

Example

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Expense Example - Putnam Dynamic Asset Allocation Conservative Fund - USD ($)	Expense Example, with Redemption, 1 Year	Expense Example, with Redemption, 3 Years	Expense Example, with Redemption, 5 Years	Expense Example, with Redemption, 10 Years
Class A	670	872	1,091	1,718
Class B	677	848	1,144	1,853
Class C	277	548	944	2,052
Class M	496	805	1,135	2,067
Class P	61	192	335	750
Class R	126	393	681	1,500
Class R5	73	227	395	883
Class R6	65	205	357	798
Class Y	76	237	411	918

Expense Example, No Redemption - Putnam Dynamic Asset Allocation Conservative Fund - USD ($)	Expense Example, No Redemption, 1 Year	Expense Example, No Redemption, 3 Years	Expense Example, No Redemption, 5 Years	Expense Example, No Redemption, 10 Years
Class B	177	548	944	1,853
Class C	177	548	944	2,052

Portfolio turnover

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 166%.

Investments, risks, and performance

Investments
The fund is one of three Putnam Dynamic Asset Allocation Funds, each of which has a unique strategic, or typical, allocation between equity and fixed-income investments. Using qualitative analysis and quantitative techniques, we adjust portfolio allocations from time to time within a certain range for each fund to try to optimize a fund’s performance consistent with its goal. The strategic allocation and the range of allowable allocation for the fund are shown below.

Class	Strategic allocation	Range
Equity	30%	15-45%
Fixed Income	70%	55-85%

We invest mainly in fixed-income investments, including U.S. and foreign government obligations, corporate obligations and securitized debt instruments (such as mortgage-backed investments). We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell fixed-income investments. We also invest, to a lesser extent, in equity securities (growth or value stocks or both) of U.S. and foreign companies of any size. We may consider, among other factors, a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell equity investments. We may also select other investments that do not fall within these asset classes. We typically use to a significant extent derivatives, such as futures, options, certain foreign currency transactions, warrants and swap contracts, for both hedging and non-hedging purposes.

Risks

It is important to understand that you can lose money by investing in the fund.

Our allocation of assets among asset classes may hurt performance. The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and value stocks may fail to rebound. These risks are generally greater for small and midsize companies.

Bond investments are subject to interest rate risk, which means the value of the fund’s bond investments is likely to fall if interest rates rise. Bond investments also are subject to credit risk, which is the risk that the issuer of the bond may default on payment of interest or principal. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (sometimes referred to as “junk bonds”), which may be considered speculative. Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage- and asset-backed investments, in other investments with less attractive terms and yields.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid. Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

Annual total returns for class A shares before sales charges

Best calendar quarter
Q2 2009  12.15%

Worst calendar quarter
Q3 2011   −5.86%

Average annual total returns after sales charges (for periods ended 12/31/18)

Average Annual Total Returns - Putnam Dynamic Asset Allocation Conservative Fund		Label	1 Year	5 Years	10 Years
Class A		before taxes	(10.25%)	2.27%	7.09%
Class A | after taxes on distributions			(11.37%)	0.78%	5.78%
Class A | after taxes on distributions and sale of fund shares			(5.51%)	1.38%	5.30%
Class B		before taxes	(10.08%)	2.36%	7.11%
Class C		before taxes	(6.47%)	2.71%	6.92%
Class M		before taxes	(8.54%)	2.24%	6.81%
Class P	[1]	before taxes	(4.39%)	3.80%	8.05%
Class R		before taxes	(4.99%)	3.22%	7.51%
Class R5	[1]	before taxes	(4.58%)	3.78%	8.05%
Class R6	[1]	before taxes	(4.44%)	3.86%	8.10%
Class Y		before taxes	(4.55%)	3.74%	8.02%
Bloomberg Barclays U.S. Aggregate Bond Index (no deduction for fees, expenses or taxes)			0.01%	2.52%	3.48%
Putnam Conservative Blended Benchmark (no deduction for fees, expenses or taxes, other than withholding taxes on reinvested dividends in the case of the MSCI EAFE Index (ND))			(1.92%)	3.97%	6.62%

The Putnam Conservative Blended Benchmark is an unmanaged index administered by Putnam Management, 65% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 25% of which is the Russell 3000 Index, 5% of which is the JPMorgan Developed High Yield Index and 5% of which is the MSCI EAFE Index (ND).

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

Class B share performance reflects conversion to class A shares after eight years.

[1] Applies only to certain redemptions of shares bought with no initial sales charge.

[2] This charge is phased out over six years.

[3] This charge is eliminated after one year.

[1] Performance for class R5 and class R6 shares prior to their inception (7/2/12) and for class P shares prior to their inception (8/31/16) is derived from the historical performance of class Y shares and has not been adjusted for the lower investor servicing fees applicable to class R5, class R6 and class P shares; had it, returns would have been higher.

XML

Label

Element

Value

Risk Return Abstract

rr_RiskReturnAbstract

Document Type

dei_DocumentType

485BPOS

Document Period End Date

dei_DocumentPeriodEndDate

Dec. 31, 2018

Registrant Name

dei_EntityRegistrantName

PUTNAM ASSET ALLOCATION FUNDS

Central Index Key

dei_EntityCentralIndexKey

0000914209

Amendment Flag

dei_AmendmentFlag

false

Trading Symbol

dei_TradingSymbol

PAEAX

Document Creation Date

dei_DocumentCreationDate

Jan. 25, 2019

Document Effective Date

dei_DocumentEffectiveDate

Jan. 30, 2019

Prospectus Date

rr_ProspectusDate

Jan. 30, 2019

Putnam Dynamic Asset Allocation Growth Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Fund Summary

Objective [Heading]

rr_ObjectiveHeading

Goal

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Putnam Dynamic Asset Allocation Growth Fund seeks capital appreciation.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 109%.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

109.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund's prospectus, in the Appendix to the fund's prospectus, and in How to buy shares beginning on page II-1 of the fund's statement of additional information (SAI).

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 50,000

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Strategy [Heading]

rr_StrategyHeading

Investments, risks, and performance

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Investments
The fund is one of three Putnam Dynamic Asset Allocation Funds, each of which has a unique strategic, or typical, allocation between equity and fixed-income investments. Using qualitative analysis and quantitative techniques, we adjust portfolio allocations from time to time within a certain range for each fund to try to optimize a fund’s performance consistent with its goal. The strategic allocation and the range of allowable allocation for the fund are shown below.

Class	Strategic allocation	Range
Equity	80%	65-95%
Fixed Income	20%	5-35%

We invest mainly in equity securities (growth or value stocks or both) of both U.S. and foreign companies of any size. We may consider, among other factors, a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell equity investments. We also invest, to a lesser extent, in fixed-income investments, including U.S. and foreign government obligations, corporate obligations and securitized debt instruments (such as mortgage-backed investments). We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell fixed-income investments. We may also select other investments that do not fall within these asset classes. We typically use to a significant extent derivatives, such as futures, options, certain foreign currency transactions, warrants and swap contracts, for both hedging and non-hedging purposes.

Risk [Heading]

rr_RiskHeading

Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

It is important to understand that you can lose money by investing in the fund.

Our allocation of assets among asset classes may hurt performance. The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and value stocks may fail to rebound. These risks are generally greater for small and midsize companies.

Bond investments are subject to interest rate risk, which means the value of the fund’s bond investments is likely to fall if interest rates rise. Bond investments also are subject to credit risk, which is the risk that the issuer of the bond may default on payment of interest or principal. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (sometimes referred to as “junk bonds”), which may be considered speculative. Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage- and asset-backed investments, in other investments with less attractive terms and yields.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid. Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

It is important to understand that you can lose money by investing in the fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time.

Performance Additional Market Index [Text]

rr_PerformanceAdditionalMarketIndex

The Putnam Growth Blended Benchmark is an unmanaged index administered by Putnam Management, 60% of which is the Russell 3000 Index, 15% of which is the MSCI EAFE Index (ND), 15% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 5% of which is the JPMorgan Developed High Yield Index and 5% of which is the MSCI Emerging Markets Index (GD).

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

putnam.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Please remember that past performance is not necessarily an indication of future results.

Bar Chart [Heading]

rr_BarChartHeading

Annual total returns for class A shares before sales charges

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

The bar chart does not reflect the impact of sales charges. If it did, performance would be lower.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best calendar quarter
Q2 2009   19.54%

Worst calendar quarter
Q3 2011 −16.16%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best calendar quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

19.54%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst calendar quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.16%)

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns after sales charges (for periods ended 12/31/18)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor's tax situation and may differ from those shown.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown for class A shares only and will vary for other classes.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

The Putnam Growth Blended Benchmark is an unmanaged index administered by Putnam Management, 60% of which is the Russell 3000 Index, 15% of which is the MSCI EAFE Index (ND), 15% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 5% of which is the JPMorgan Developed High Yield Index and 5% of which is the MSCI Emerging Markets Index (GD).

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

Class B share performance reflects conversion to class A shares after eight years.

Putnam Dynamic Asset Allocation Growth Fund | Class A

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[1]

Management fees)

rr_ManagementFeesOverAssets

0.59%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.23%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.07%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 678

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

896

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,131

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,806

Annual Return 2009

rr_AnnualReturn2009

36.88%

Annual Return 2010

rr_AnnualReturn2010

14.93%

Annual Return 2011

rr_AnnualReturn2011

(4.24%)

Annual Return 2012

rr_AnnualReturn2012

16.86%

Annual Return 2013

rr_AnnualReturn2013

24.83%

Annual Return 2014

rr_AnnualReturn2014

8.99%

Annual Return 2015

rr_AnnualReturn2015

(0.28%)

Annual Return 2016

rr_AnnualReturn2016

7.84%

Annual Return 2017

rr_AnnualReturn2017

19.85%

Annual Return 2018

rr_AnnualReturn2018

(9.71%)

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(14.90%)

5 Years

rr_AverageAnnualReturnYear05

3.63%

10 Years

rr_AverageAnnualReturnYear10

10.14%

Putnam Dynamic Asset Allocation Growth Fund | Class B

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

5.00%

^[2]

Management fees)

rr_ManagementFeesOverAssets

0.59%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.23%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.82%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 685

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

873

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,185

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,940

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

185

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

573

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

985

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,940

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(14.45%)

5 Years

rr_AverageAnnualReturnYear05

3.80%

10 Years

rr_AverageAnnualReturnYear10

10.14%

Putnam Dynamic Asset Allocation Growth Fund | Class C

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[3]

Management fees)

rr_ManagementFeesOverAssets

0.59%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.23%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.82%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 285

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

573

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

985

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,137

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

185

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

573

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

985

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,137

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(11.22%)

5 Years

rr_AverageAnnualReturnYear05

4.07%

10 Years

rr_AverageAnnualReturnYear10

9.96%

Putnam Dynamic Asset Allocation Growth Fund | Class M

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

3.50%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.59%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.75%

Other expenses

rr_OtherExpensesOverAssets

0.23%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.57%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 504

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

828

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,175

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 2,152

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(13.29%)

5 Years

rr_AverageAnnualReturnYear05

3.60%

10 Years

rr_AverageAnnualReturnYear10

9.86%

Putnam Dynamic Asset Allocation Growth Fund | Class P

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.59%

Other expenses

rr_OtherExpensesOverAssets

0.07%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.66%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 67

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

211

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

368

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 822

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(9.30%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

5.21%

^[4]

10 Years

rr_AverageAnnualReturnYear10

11.11%

^[4]

Putnam Dynamic Asset Allocation Growth Fund | Class R

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.59%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

0.23%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.32%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 134

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

418

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

723

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,590

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(9.89%)

5 Years

rr_AverageAnnualReturnYear05

4.60%

10 Years

rr_AverageAnnualReturnYear10

10.51%

Putnam Dynamic Asset Allocation Growth Fund | Class R5

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.59%

Other expenses

rr_OtherExpensesOverAssets

0.21%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.80%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 82

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

255

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

444

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 990

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(9.41%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

5.15%

^[4]

10 Years

rr_AverageAnnualReturnYear10

11.08%

^[4]

Putnam Dynamic Asset Allocation Growth Fund | Class R6

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.59%

Other expenses

rr_OtherExpensesOverAssets

0.11%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.70%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 72

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

224

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

390

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 871

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(9.34%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

5.24%

^[4]

10 Years

rr_AverageAnnualReturnYear10

11.15%

^[4]

Putnam Dynamic Asset Allocation Growth Fund | Class Y

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.59%

Other expenses

rr_OtherExpensesOverAssets

0.23%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.82%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 84

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

262

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

455

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,014

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(9.41%)

5 Years

rr_AverageAnnualReturnYear05

5.14%

10 Years

rr_AverageAnnualReturnYear10

11.07%

Putnam Dynamic Asset Allocation Growth Fund | after taxes on distributions | Class A

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(17.20%)

5 Years

rr_AverageAnnualReturnYear05

1.24%

10 Years

rr_AverageAnnualReturnYear10

8.54%

Putnam Dynamic Asset Allocation Growth Fund | after taxes on distributions and sale of fund shares | Class A

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(7.86%)

5 Years

rr_AverageAnnualReturnYear05

2.32%

10 Years

rr_AverageAnnualReturnYear10

7.96%

Putnam Dynamic Asset Allocation Growth Fund | Russell 3000 Index (no deduction for fees, expenses or taxes)

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.24%)

^[5]

5 Years

rr_AverageAnnualReturnYear05

7.91%

^[5]

10 Years

rr_AverageAnnualReturnYear10

13.18%

^[5]

Putnam Dynamic Asset Allocation Growth Fund | Putnam Growth Blended Benchmark (no deduction for fees, expenses or taxes, other than withholding taxes on reinvested dividends in the case of the MSCI EAFE Index (ND))

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.91%)

5 Years

rr_AverageAnnualReturnYear05

5.63%

10 Years

rr_AverageAnnualReturnYear10

10.55%

Putnam Dynamic Asset Allocation Balanced Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Fund Summary

Objective [Heading]

rr_ObjectiveHeading

Goal

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Putnam Dynamic Asset Allocation Balanced Fund seeks total return. Total return is composed of capital appreciation and income.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 129%.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

129.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund's prospectus, in the Appendix to the fund's prospectus, and in How to buy shares beginning on page II-1 of the fund's statement of additional information (SAI).

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 50,000

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Strategy [Heading]

rr_StrategyHeading

Investments, risks, and performance

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Investments
The fund is one of three Putnam Dynamic Asset Allocation Funds, each of which has a unique strategic, or typical, allocation between equity and fixed-income investments. Using qualitative analysis and quantitative techniques, we adjust portfolio allocations from time to time within a certain range for each fund to try to optimize a fund’s performance consistent with its goal. The strategic allocation and the range of allowable allocation for the fund are shown below.

Class	Strategic allocation	Range
Equity	60%	45-75%
Fixed Income	40%	25-55%

We invest mainly in equity securities (growth or value stocks or both) of both U.S. and foreign companies of any size. We may consider, among other factors, a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell equity investments. We also invest in fixed-income investments, including U.S. and foreign government obligations, corporate obligations and securitized debt instruments (such as mortgage-backed investments). We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell fixed-income investments. We may also select other investments that do not fall within these asset classes. We typically use to a significant extent derivatives, such as futures, options, certain foreign currency transactions, warrants and swap contracts, for both hedging and non-hedging purposes.

Risk [Heading]

rr_RiskHeading

Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

It is important to understand that you can lose money by investing in the fund.

Our allocation of assets among asset classes may hurt performance. The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and value stocks may fail to rebound. These risks are generally greater for small and midsize companies.

Bond investments are subject to interest rate risk, which means the value of the fund’s bond investments is likely to fall if interest rates rise. Bond investments also are subject to credit risk, which is the risk that the issuer of the bond may default on payment of interest or principal. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (sometimes referred to as “junk bonds”), which may be considered speculative. Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage- and asset-backed investments, in other investments with less attractive terms and yields.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid. Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

It is important to understand that you can lose money by investing in the fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time.

Performance Additional Market Index [Text]

rr_PerformanceAdditionalMarketIndex

The Putnam Balanced Blended Benchmark is an unmanaged index administered by Putnam Management, 50% of which is the Russell 3000 Index, 35% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 10% of which is the MSCI EAFE Index (ND) and 5% of which is the JPMorgan Developed High Yield Index.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

putnam.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Please remember that past performance is not necessarily an indication of future results.

Bar Chart [Heading]

rr_BarChartHeading

Annual total returns for class A shares before sales charges

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

The bar chart does not reflect the impact of sales charges. If it did, performance would be lower.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best calendar quarter
Q2 2009  16.13%

Worst calendar quarter
Q3 2011   −11.35%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best calendar quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.13%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst calendar quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(11.35%)

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns after sales charges (for periods ended 12/31/18)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor's tax situation and may differ from those shown.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown for class A shares only and will vary for other classes.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

The Putnam Balanced Blended Benchmark is an unmanaged index administered by Putnam Management, 50% of which is the Russell 3000 Index, 35% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 10% of which is the MSCI EAFE Index (ND) and 5% of which is the JPMorgan Developed High Yield Index.

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

Class B share performance reflects conversion to class A shares after eight years.

Putnam Dynamic Asset Allocation Balanced Fund | Class A

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[1]

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.97%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 668

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

866

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,080

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,696

Annual Return 2009

rr_AnnualReturn2009

35.20%

Annual Return 2010

rr_AnnualReturn2010

14.36%

Annual Return 2011

rr_AnnualReturn2011

(0.62%)

Annual Return 2012

rr_AnnualReturn2012

14.14%

Annual Return 2013

rr_AnnualReturn2013

19.00%

Annual Return 2014

rr_AnnualReturn2014

9.44%

Annual Return 2015

rr_AnnualReturn2015

0.30%

Annual Return 2016

rr_AnnualReturn2016

6.69%

Annual Return 2017

rr_AnnualReturn2017

15.18%

Annual Return 2018

rr_AnnualReturn2018

(7.21%)

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(12.54%)

5 Years

rr_AverageAnnualReturnYear05

3.36%

10 Years

rr_AverageAnnualReturnYear10

9.43%

Putnam Dynamic Asset Allocation Balanced Fund | Class B

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

5.00%

^[2]

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.72%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 675

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

842

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,133

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,831

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

175

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

542

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

933

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,831

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(12.19%)

5 Years

rr_AverageAnnualReturnYear05

3.48%

10 Years

rr_AverageAnnualReturnYear10

9.43%

Putnam Dynamic Asset Allocation Balanced Fund | Class C

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[3]

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.72%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 275

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

542

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

933

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,030

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

175

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

542

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

933

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,030

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(8.77%)

5 Years

rr_AverageAnnualReturnYear05

3.81%

10 Years

rr_AverageAnnualReturnYear10

9.26%

Putnam Dynamic Asset Allocation Balanced Fund | Class M

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

3.50%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.75%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.47%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 494

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

799

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,125

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 2,046

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(10.92%)

5 Years

rr_AverageAnnualReturnYear05

3.34%

10 Years

rr_AverageAnnualReturnYear10

9.14%

Putnam Dynamic Asset Allocation Balanced Fund | Class P

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.06%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.58%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 59

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

186

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

324

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 726

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(6.81%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

4.93%

^[4]

10 Years

rr_AverageAnnualReturnYear10

10.40%

^[4]

Putnam Dynamic Asset Allocation Balanced Fund | Class R

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.22%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 124

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

387

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

670

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,477

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(7.43%)

5 Years

rr_AverageAnnualReturnYear05

4.32%

10 Years

rr_AverageAnnualReturnYear10

9.80%

Putnam Dynamic Asset Allocation Balanced Fund | Class R5

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.72%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 74

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

230

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

401

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 894

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(6.95%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

4.86%

^[4]

10 Years

rr_AverageAnnualReturnYear10

10.37%

^[4]

Putnam Dynamic Asset Allocation Balanced Fund | Class R6

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.10%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.62%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 63

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

199

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

346

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 774

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(6.86%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

4.97%

^[4]

10 Years

rr_AverageAnnualReturnYear10

10.44%

^[4]

Putnam Dynamic Asset Allocation Balanced Fund | Class Y

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.72%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 74

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

230

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

401

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 894

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(6.95%)

5 Years

rr_AverageAnnualReturnYear05

4.86%

10 Years

rr_AverageAnnualReturnYear10

10.37%

Putnam Dynamic Asset Allocation Balanced Fund | after taxes on distributions | Class A

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.42%)

5 Years

rr_AverageAnnualReturnYear05

1.72%

10 Years

rr_AverageAnnualReturnYear10

8.07%

Putnam Dynamic Asset Allocation Balanced Fund | after taxes on distributions and sale of fund shares | Class A

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(6.43%)

5 Years

rr_AverageAnnualReturnYear05

2.34%

10 Years

rr_AverageAnnualReturnYear10

7.37%

Putnam Dynamic Asset Allocation Balanced Fund | Russell 3000 Index (no deduction for fees, expenses or taxes)

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.24%)

^[5]

5 Years

rr_AverageAnnualReturnYear05

7.91%

^[5]

10 Years

rr_AverageAnnualReturnYear10

13.18%

^[5]

Putnam Dynamic Asset Allocation Balanced Fund | Putnam Balanced Blended Benchmark (no deduction for fees, expenses or taxes, other than withholding taxes on reinvested dividends in the case of the MSCI EAFE Index (ND))

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(3.90%)

5 Years

rr_AverageAnnualReturnYear05

5.24%

10 Years

rr_AverageAnnualReturnYear10

9.22%

Putnam Dynamic Asset Allocation Conservative Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Fund Summary

Objective [Heading]

rr_ObjectiveHeading

Goal

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Putnam Dynamic Asset Allocation Conservative Fund seeks total return consistent with preservation of capital. Total return is composed of capital appreciation and income.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund’s prospectus, in the Appendix to the fund’s prospectus, and in How to buy shares beginning on page II-1 of the fund’s statement of additional information (SAI).

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction-related costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher turnover rate may indicate higher transaction costs and may result in higher taxes when the fund’s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or the above example, affect fund performance. The fund’s turnover rate in the most recent fiscal year was 166%.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

166.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Putnam funds. More information about these and other discounts is available from your financial advisor and in How do I buy fund shares? beginning on page 27 of the fund's prospectus, in the Appendix to the fund's prospectus, and in How to buy shares beginning on page II-1 of the fund's statement of additional information (SAI).

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 50

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Strategy [Heading]

rr_StrategyHeading

Investments, risks, and performance

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Investments
The fund is one of three Putnam Dynamic Asset Allocation Funds, each of which has a unique strategic, or typical, allocation between equity and fixed-income investments. Using qualitative analysis and quantitative techniques, we adjust portfolio allocations from time to time within a certain range for each fund to try to optimize a fund’s performance consistent with its goal. The strategic allocation and the range of allowable allocation for the fund are shown below.

Class	Strategic allocation	Range
Equity	30%	15-45%
Fixed Income	70%	55-85%

We invest mainly in fixed-income investments, including U.S. and foreign government obligations, corporate obligations and securitized debt instruments (such as mortgage-backed investments). We may consider, among other factors, credit, interest rate and prepayment risks, as well as general market conditions, when deciding whether to buy or sell fixed-income investments. We also invest, to a lesser extent, in equity securities (growth or value stocks or both) of U.S. and foreign companies of any size. We may consider, among other factors, a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell equity investments. We may also select other investments that do not fall within these asset classes. We typically use to a significant extent derivatives, such as futures, options, certain foreign currency transactions, warrants and swap contracts, for both hedging and non-hedging purposes.

Risk [Heading]

rr_RiskHeading

Risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

It is important to understand that you can lose money by investing in the fund.

Our allocation of assets among asset classes may hurt performance. The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and value stocks may fail to rebound. These risks are generally greater for small and midsize companies.

Bond investments are subject to interest rate risk, which means the value of the fund’s bond investments is likely to fall if interest rates rise. Bond investments also are subject to credit risk, which is the risk that the issuer of the bond may default on payment of interest or principal. Interest rate risk is generally greater for longer-term bonds, and credit risk is generally greater for below-investment-grade bonds (sometimes referred to as “junk bonds”), which may be considered speculative. Mortgage-backed investments, unlike traditional debt investments, are also subject to prepayment risk, which means that they may increase in value less than other bonds when interest rates decline and decline in value more than other bonds when interest rates rise. We may have to invest the proceeds from prepaid investments, including mortgage- and asset-backed investments, in other investments with less attractive terms and yields.

The value of international investments traded in foreign currencies may be adversely impacted by fluctuations in exchange rates. International investments, particularly investments in emerging markets, may carry risks associated with potentially less stable economies or governments (such as the risk of seizure by a foreign government, the imposition of currency or other restrictions, or high levels of inflation), and may be or become illiquid. Our use of derivatives may increase the risks of investing in the fund by increasing investment exposure (which may be considered leverage) or, in the case of many over-the-counter instruments, because of the potential inability to terminate or sell derivatives positions and the potential failure of the other party to the instrument to meet its obligations.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

It is important to understand that you can lose money by investing in the fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time. The bar chart does not reflect the impact of sales charges. If it did, performance would be lower. Please remember that past performance is not necessarily an indication of future results. Monthly performance figures for the fund are available at putnam.com.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The performance information below gives some indication of the risks associated with an investment in the fund by showing the fund’s performance year to year and over time.

Performance Additional Market Index [Text]

rr_PerformanceAdditionalMarketIndex

The Putnam Conservative Blended Benchmark is an unmanaged index administered by Putnam Management, 65% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 25% of which is the Russell 3000 Index, 5% of which is the JPMorgan Developed High Yield Index and 5% of which is the MSCI EAFE Index (ND).

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

putnam.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Please remember that past performance is not necessarily an indication of future results.

Bar Chart [Heading]

rr_BarChartHeading

Annual total returns for class A shares before sales charges

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

The bar chart does not reflect the impact of sales charges. If it did, performance would be lower.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best calendar quarter
Q2 2009  12.15%

Worst calendar quarter
Q3 2011   −5.86%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best calendar quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

12.15%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst calendar quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(5.86%)

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns after sales charges (for periods ended 12/31/18)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor's tax situation and may differ from those shown.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns are shown for class A shares only and will vary for other classes.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

The Putnam Conservative Blended Benchmark is an unmanaged index administered by Putnam Management, 65% of which is the Bloomberg Barclays U.S. Aggregate Bond Index, 25% of which is the Russell 3000 Index, 5% of which is the JPMorgan Developed High Yield Index and 5% of which is the MSCI EAFE Index (ND).

After-tax returns reflect the historical highest individual federal marginal income tax rates and do not reflect state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are shown for class A shares only and will vary for other classes. These after-tax returns do not apply if you hold your fund shares through a 401(k) plan, an IRA, or another tax-advantaged arrangement.

Class B share performance reflects conversion to class A shares after eight years.

Putnam Dynamic Asset Allocation Conservative Fund | Class A

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[1]

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.99%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 670

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

872

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,091

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,718

Annual Return 2009

rr_AnnualReturn2009

30.47%

Annual Return 2010

rr_AnnualReturn2010

10.75%

Annual Return 2011

rr_AnnualReturn2011

1.47%

Annual Return 2012

rr_AnnualReturn2012

10.52%

Annual Return 2013

rr_AnnualReturn2013

9.42%

Annual Return 2014

rr_AnnualReturn2014

8.21%

Annual Return 2015

rr_AnnualReturn2015

0.36%

Annual Return 2016

rr_AnnualReturn2016

4.60%

Annual Return 2017

rr_AnnualReturn2017

9.72%

Annual Return 2018

rr_AnnualReturn2018

(4.78%)

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(10.25%)

5 Years

rr_AverageAnnualReturnYear05

2.27%

10 Years

rr_AverageAnnualReturnYear10

7.09%

Putnam Dynamic Asset Allocation Conservative Fund | Class B

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

5.00%

^[2]

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.74%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 677

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

848

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,144

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,853

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

177

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

548

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

944

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,853

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(10.08%)

5 Years

rr_AverageAnnualReturnYear05

2.36%

10 Years

rr_AverageAnnualReturnYear10

7.11%

Putnam Dynamic Asset Allocation Conservative Fund | Class C

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[3]

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.74%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 277

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

548

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

944

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,052

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

177

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

548

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

944

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,052

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(6.47%)

5 Years

rr_AverageAnnualReturnYear05

2.71%

10 Years

rr_AverageAnnualReturnYear10

6.92%

Putnam Dynamic Asset Allocation Conservative Fund | Class M

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

3.50%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.75%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.49%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 496

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

805

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,135

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 2,067

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(8.54%)

5 Years

rr_AverageAnnualReturnYear05

2.24%

10 Years

rr_AverageAnnualReturnYear10

6.81%

Putnam Dynamic Asset Allocation Conservative Fund | Class P

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.08%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.60%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 61

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

192

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

335

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 750

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(4.39%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

3.80%

^[4]

10 Years

rr_AverageAnnualReturnYear10

8.05%

^[4]

Putnam Dynamic Asset Allocation Conservative Fund | Class R

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.24%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 126

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

393

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

681

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,500

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(4.99%)

5 Years

rr_AverageAnnualReturnYear05

3.22%

10 Years

rr_AverageAnnualReturnYear10

7.51%

Putnam Dynamic Asset Allocation Conservative Fund | Class R5

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.19%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.71%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 73

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

227

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

395

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 883

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(4.58%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

3.78%

^[4]

10 Years

rr_AverageAnnualReturnYear10

8.05%

^[4]

Putnam Dynamic Asset Allocation Conservative Fund | Class R6

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.12%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.64%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 65

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

205

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

357

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 798

Label

rr_AverageAnnualReturnLabel

before taxes

^[4]

1 Year

rr_AverageAnnualReturnYear01

(4.44%)

^[4]

5 Years

rr_AverageAnnualReturnYear05

3.86%

^[4]

10 Years

rr_AverageAnnualReturnYear10

8.10%

^[4]

Putnam Dynamic Asset Allocation Conservative Fund | Class Y

Risk Return Abstract

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, whichever is lower)

rr_MaximumDeferredSalesChargeOverOther

none

Management fees)

rr_ManagementFeesOverAssets

0.52%

Other expenses

rr_OtherExpensesOverAssets

0.22%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.74%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 76

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

237

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

411

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 918

Label

rr_AverageAnnualReturnLabel

before taxes

1 Year

rr_AverageAnnualReturnYear01

(4.55%)

5 Years

rr_AverageAnnualReturnYear05

3.74%

10 Years

rr_AverageAnnualReturnYear10

8.02%

Putnam Dynamic Asset Allocation Conservative Fund | after taxes on distributions | Class A

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(11.37%)

5 Years

rr_AverageAnnualReturnYear05

0.78%

10 Years

rr_AverageAnnualReturnYear10

5.78%

Putnam Dynamic Asset Allocation Conservative Fund | after taxes on distributions and sale of fund shares | Class A

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.51%)

5 Years

rr_AverageAnnualReturnYear05

1.38%

10 Years

rr_AverageAnnualReturnYear10

5.30%

Putnam Dynamic Asset Allocation Conservative Fund | Bloomberg Barclays U.S. Aggregate Bond Index (no deduction for fees, expenses or taxes)

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.01%

5 Years

rr_AverageAnnualReturnYear05

2.52%

10 Years

rr_AverageAnnualReturnYear10

3.48%

Putnam Dynamic Asset Allocation Conservative Fund | Putnam Conservative Blended Benchmark (no deduction for fees, expenses or taxes, other than withholding taxes on reinvested dividends in the case of the MSCI EAFE Index (ND))

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.92%)

5 Years

rr_AverageAnnualReturnYear05

3.97%

10 Years

rr_AverageAnnualReturnYear10

6.62%

[1] Applies only to certain redemptions of shares bought with no initial sales charge.

[2] This charge is phased out over six years.

[3] This charge is eliminated after one year.

[4] Performance for class R5 and class R6 shares prior to their inception (7/2/12) and for class P shares prior to their inception (8/31/16) is derived from the historical performance of class Y shares and has not been adjusted for the lower investor servicing fees applicable to class R5, class R6 and class P shares; had it, returns would have been higher.

[5] Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to the Russell Indexes. Russell(R) is a trademark of Frank Russell Company.