CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Condensed Income Statements, Captions [Line Items]
Operating expenses reflected in net operating income	$ (755.4)	$ (794.8)
Income before income taxes	206.9	735.3
Net income (loss) attributable to redeemable non-controlling interests	(176.5)	41.4
Consolidation eliminations
Condensed Income Statements, Captions [Line Items]
Operating expenses reflected in net operating income	(2.5)	(1.5)
Consolidated T. Rowe Price investment products
Condensed Income Statements, Captions [Line Items]
Income before income taxes	(334.0)	98.8
Net income (loss) attributable to T. Rowe Price Group	(157.5)	41.4
Net income (loss) attributable to redeemable non-controlling interests	(176.5)	57.4
Consolidated T. Rowe Price investment products \| Reportable entities
Condensed Income Statements, Captions [Line Items]
Operating expenses reflected in net operating income	(3.7)	(3.1)
Net investment income (loss) reflected in non-operating income (loss)	(330.3)	101.9
Income before income taxes	(334.0)	98.8
Voting interest entities
Condensed Income Statements, Captions [Line Items]
Income before income taxes	(35.4)	7.7
Net income (loss) attributable to T. Rowe Price Group	(22.6)	(1.0)
Net income (loss) attributable to redeemable non-controlling interests	(12.8)	8.7
Voting interest entities \| Reportable entities
Condensed Income Statements, Captions [Line Items]
Operating expenses reflected in net operating income	(0.2)	(0.3)
Net investment income (loss) reflected in non-operating income (loss)	(35.2)	8.0
Income before income taxes	(35.4)	7.7
Variable interest entities
Condensed Income Statements, Captions [Line Items]
Income before income taxes	(298.6)	91.1
Net income (loss) attributable to T. Rowe Price Group	(134.9)	42.4
Net income (loss) attributable to redeemable non-controlling interests	(163.7)	48.7
Variable interest entities \| Reportable entities
Condensed Income Statements, Captions [Line Items]
Operating expenses reflected in net operating income	(3.5)	(2.8)
Net investment income (loss) reflected in non-operating income (loss)	(295.1)	93.9
Income before income taxes	$ (298.6)	$ 91.1

No definition available.

Name:	srt_CondensedIncomeStatementsCaptionsLineItems
Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Income (Loss) from Continuing Operations before Income Taxes, Attributable to Parent

+ References

No definition available.

+ Details

Name:	trow_IncomeLossfromContinuingOperationsbeforeIncomeTaxesAttributabletoParent
Namespace Prefix:	trow_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68072869&loc=d3e41242-110953

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(10))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(8))
-URI http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(15))
-URI http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a),(b))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

Name:	us-gaap_InvestmentIncomeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

+ References

+ Details

Name:	us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	srt_ConsolidationItemsAxis=srt_ConsolidationEliminationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	trow_InvestmentsByConsolidatedAndNonconsolidatedEntitiesAxis=trow_ConsolidatedInvestmentPortfoliosMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=srt_ReportableLegalEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	trow_InvestmentsByConsolidatedAndNonconsolidatedEntitiesAxis=trow_VotingInterestEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	trow_InvestmentsByConsolidatedAndNonconsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: