Untitled Document

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Dec. 31, 2017
Registrant Name	dei_EntityRegistrantName	T. Rowe Price New America Growth Fund, Inc.
Central Index Key	dei_EntityCentralIndexKey	0000773485
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Apr. 26, 2018
Document Effective Date	dei_DocumentEffectiveDate	May 01, 2018
Prospectus Date	rr_ProspectusDate	May 01, 2018

Risk/Return:

rr_RiskReturnAbstract

Prospectus Date

rr_ProspectusDate

May 01, 2018

Risk/Return:

rr_RiskReturnAbstract

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Fees and Expenses of the Fund

Shareholder fees (fees paid directly from your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

74.90%

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods, that your investment has a 5% return each year, and that the fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund invests primarily (at least 65% of its total assets) in common stocks of U.S. companies operating in those sectors of the economy that, in T. Rowe Price’s view, are the fastest growing or have the greatest growth potential. The U.S. economy continues to evolve, in part because of the application of new technologies and scientific advances. Growing companies that are positioned to benefit from dynamic technological, social, medical, and business developments that help define the current U.S. economic landscape can be found across an array of industries. The fund’s allocation to industry sectors will generally reflect such factors as the overall revenue growth of the component companies in a sector and the sector’s contribution to U.S. gross domestic product from year to year, although the fund may at times invest significantly in stocks of information technology companies.

Holdings range from large-cap to small-cap companies. In selecting stocks, the advisor looks for many characteristics, typically including, but not limited to:

earnings growth rates that generally exceed that of the average company in the Russell 1000 Growth Index;

favorable company fundamentals, such as a strong balance sheet, sound business strategy, and promising competitive positioning;

effective management; or

stock valuations, such as price/earnings or price/cash flow ratios, that seem reasonable relative to the company’s prospects.

In pursuing its investment objective, the fund has the discretion to deviate from its normal investment criteria. These situations might arise when the fund’s adviser believes a security could increase in value for a variety of reasons, including an extraordinary corporate event, a new product introduction or innovation, a favorable competitive development, or a change in management.

While most assets will typically be invested in U.S. common stocks, the fund may invest in foreign stocks in keeping with the fund’s objective. The fund may at times invest significantly in certain sectors, such as the information technology sector.

The fund may sell securities for a variety of reasons, such as to secure gains, limit losses, or redeploy assets into more promising opportunities.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

As with any mutual fund, there is no guarantee that the fund will achieve its objective. The fund’s share price fluctuates, which means you could lose money by investing in the fund. The principal risks of investing in this fund are summarized as follows:

Active management risks The investment adviser’s judgments about the attractiveness, value, or potential appreciation of the fund’s investments may prove to be incorrect. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies if the fund’s overall investment selections or strategies fail to produce the intended results.

Risks of U.S. stock investing Stocks generally fluctuate in value more than bonds and may decline significantly over short time periods. There is a chance that stock prices overall will decline because stock markets tend to move in cycles, with periods of rising and falling prices. The value of a stock in which the fund invests may decline due to general weakness in the U.S. stock market, such as when the U.S. financial markets decline, or because of factors that affect a particular company or industry.

Investment style risks Different investment styles tend to shift in and out of favor depending on market conditions and investor sentiment. The fund’s growth approach to investing could cause it to underperform other stock funds that employ a different investment style. Growth stocks tend to be more volatile than certain other types of stocks, and their prices may fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings and may lack dividends that can help cushion its share price in a declining market.

Market capitalization risks Because the fund may invest in companies of any size, its share price could be more volatile than a fund that invests only in large companies. Small and medium-sized companies often have less experienced management, narrower product lines, more limited financial resources, and less publicly available information than larger companies. Larger companies may not be able to attain the high growth rates of successful smaller companies, especially during strong economic periods, and they may be less capable of responding quickly to competitive challenges and industry changes.

Sector concentration risks At times, the fund may have a significant portion of its assets invested in securities of companies conducting business in a broadly related group of industries within an economic sector. Companies in the same economic sector may be similarly affected by economic or market events, making the fund more vulnerable to unfavorable developments in that economic sector than funds that invest more broadly. For example, the fund may have a significant portion of its assets invested in securities of companies in the information technology sector. Companies in the information technology sector can be adversely affected by, among other things, intense competition, earnings disappointments, and rapid obsolescence of products and services due to technological innovations or changing consumer preferences.

Foreign investing risks The fund’s investments in foreign securities may be adversely affected by local, political, social, and economic conditions overseas, greater volatility, reduced liquidity, or decreases in foreign currency values relative to the U.S. dollar. These risks are heightened for the fund’s investments in emerging markets, which are more susceptible to governmental interference, less efficient trading markets, and the imposition of local taxes or restrictions on gaining access to sales proceeds for foreign investors.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following performance information provides some indication of the risks of investing in the fund.

The following bar chart illustrates how much returns can differ from year to year by showing calendar year returns and the best and worst calendar quarter returns during those years for the fund’s Investor Class. Returns for other share classes vary since they have different expenses.

The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year, and also compares the returns with the returns of a relevant broad-based market index, as well as with the returns of one or more comparative indexes that have investment characteristics similar to those of the fund.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund's performance information represents only past performance (before and after taxes) and is not necessarily an indication of future results.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

	Quarter Ended	Total Return		Quarter Ended	Total Return
Best Quarter	6/30/09	18.70%	Worst Quarter	12/31/08	-25.70%

Performance Table Market Index Changed

rr_PerformanceTableMarketIndexChanged

Effective March 1, 2018, the Russell 1000 Growth Index replaced the S&P 500 Index as the fund’s primary benchmark. The Russell 1000 Growth Index is a more appropriate, style-specific benchmark that better aligns with the fund’s growth-focused investment style.

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. After-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or an IRA.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year, and also compares the returns with the returns of a relevant broad-based market index, as well as with the returns of one or more comparative indexes that have investment characteristics similar to those of the fund.

In addition, the table shows hypothetical after-tax returns to demonstrate how taxes paid by a shareholder may influence returns. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or an IRA. After-tax returns are shown only for the Investor Class and will differ for other share classes.

Maximum account fee

rr_MaximumAccountFee

$ 20

^[1]

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

Total annual fund operating expenses

rr_ExpensesOverAssets

0.79%

3 years

rr_ExpenseExampleYear03

252

10 years

rr_ExpenseExampleYear10

$ 978

2009

rr_AnnualReturn2009

49.33%

2011

rr_AnnualReturn2011

(0.41%)

2013

rr_AnnualReturn2013

37.73%

2015

rr_AnnualReturn2015

8.80%

2017

rr_AnnualReturn2017

34.57%

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst Quarter

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(25.70%)

5 Years

rr_AverageAnnualReturnYear05

17.48%

Since inception

rr_AverageAnnualReturnSinceInception

Maximum account fee

rr_MaximumAccountFee

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

Total annual fund operating expenses

rr_ExpensesOverAssets

0.66%

3 years

rr_ExpenseExampleYear03

211

10 years

rr_ExpenseExampleYear10

$ 822

5 Years

rr_AverageAnnualReturnYear05

Since inception

rr_AverageAnnualReturnSinceInception

16.45%

Maximum account fee

rr_MaximumAccountFee

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.06%

3 years

rr_ExpenseExampleYear03

337

10 years

rr_ExpenseExampleYear10

$ 1,294

5 Years

rr_AverageAnnualReturnYear05

17.17%

Since inception

rr_AverageAnnualReturnSinceInception

1 Year

rr_AverageAnnualReturnYear01

30.70%

10 Years

rr_AverageAnnualReturnYear10

9.11%

Inception date

rr_AverageAnnualReturnInceptionDate

Sep. 30, 1985

Risk/Return:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

13.30%

Since inception

rr_AverageAnnualReturnSinceInception

1 Year

rr_AverageAnnualReturnYear01

30.21%

^[2]

10 Years

rr_AverageAnnualReturnYear10

10.00%

^[2]

Inception date

rr_AverageAnnualReturnInceptionDate

Dec. 17, 2015

^[2]

Risk/Return:

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

15.79%

Since inception

rr_AverageAnnualReturnSinceInception

16.54%

^[3]

1 Year

rr_AverageAnnualReturnYear01

28.76%

10 Years

rr_AverageAnnualReturnYear10

8.33%

Inception date

rr_AverageAnnualReturnInceptionDate

Dec. 17, 2015


Exhibit	Exhibit No.
XBRL Instance Document	EX-101.INS
XBRL Taxonomy Extension Schema Document	EX-101.SCH
XBRL Taxonomy Extension Calculation Linkbase Document	EX-101.CAL
XBRL Taxonomy Extension Definition Linkbase Document	EX-101.DEF
XBRL Taxonomy Extension Labels Linkbase Document	EX-101.LAB
XBRL Taxonomy Extension Presentation Linkbase Document	EX-101.PRE


Signature	Title	Date


/s/Edward C. Bernard	Chairman of the Board	May 15, 2018
Edward C. Bernard	(Chief Executive Officer)


/s/Catherine D. Mathews	Treasurer	May 15, 2018
Catherine D. Mathews	(Chief Financial Officer)
	and Vice President

*
Teresa Bryce Bazemore	Director	May 15, 2018


*
Ronald J. Daniels	Director	May 15, 2018


*
Bruce W. Duncan	Director	May 15, 2018


*
Robert J. Gerrard, Jr.	Director	May 15, 2018


*
Paul F. McBride	Director	May 15, 2018


*
Cecilia E. Rouse	Director	May 15, 2018


*
John G. Schreiber	Director	May 15, 2018



/s/Robert W. Sharps	Director and Vice President	May 15, 2018
Robert W. Sharps


*
Mark. R. Tercek	Director	May 15, 2018


*/s/David Oestreicher	Vice President and	May 15, 2018
David Oestreicher	Attorney-In-Fact


ALL CORPORATIONS/TRUSTS /s/Edward C. Bernard
Edward C. Bernard /s/Catherine D. Mathews	Chairman of the Board (Principal Executive Officer) Director/Trustee	April 27, 2017
Catherine D. Mathews /s/Anthony W. Deering	Treasurer (Principal Financial Officer) Vice President	April 27, 2017
Anthony W. Deering /s/Bruce W. Duncan	Director/Trustee	April 27, 2017
Bruce W. Duncan /s/Robert J. Gerrard, Jr.	Director/Trustee	April 27, 2017
Robert J. Gerrard, Jr. /s/Paul F. McBride	Director/Trustee	April 27, 2017
Paul F. McBride /s/Cecilia E. Rouse	Director/Trustee	April 27, 2017
Cecilia E. Rouse /s/John G. Schreiber	Director/Trustee	April 27, 2017
John G. Schreiber /s/Mark R. Tercek	Director/Trustee	April 27, 2017
Mark R. Tercek	Director/Trustee	April 27, 2017


/s/Teresa Bryce Bazemore
Teresa Bryce Bazemore, Director	Date: January 1, 2018


/s/Ronald J. Daniels
Ronald J. Daniels, Director	Date: January 1, 2018


Darrell N. Braman, Secretary


Darrell N. Braman, Secretary


Darrell N. Braman, Secretary