Tax Cuts And Jobs Act Of 2017, Reclassification From AOCI To Retained Earnings, Available-For-Sale Investments, Tax Effect

No definition available.

+ Details

Name:	trow_TaxCutsAndJobsActOf2017ReclassificationFromAOCIToRetainedEarningsAvailableForSaleInvestmentsTaxEffect
Namespace Prefix:	trow_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

- Definition

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_RetainedEarningsUnappropriatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedOtherComprehensiveIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis=us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=trow_AccumulatedNetInvestmentGainLossNetGainsLossesRealizedonDispositionsofSecuritiesAttributabletoParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedTranslationAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidatedEntitiesAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME. (Reclassification Adjustments) (Details) - USD ($) $ in Millions		3 Months Ended
	Dec. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Reclassification adjustment out of accumulated other comprehensive income
Non-operating income		$ (16.1)	$ (115.0)
Provision for income taxes		144.4	236.3
Retained earnings [Member]
Reclassification adjustment out of accumulated other comprehensive income
Reclassification adjustment of stranded taxes on available-for-sale investments	$ 1.7
Total accumulated other comprehensive income (loss) [Member]
Reclassification adjustment out of accumulated other comprehensive income
Reclassification adjustment of stranded taxes on available-for-sale investments	$ (1.7)
Reclassification out of accumulated other comprehensive income [Member] \| Net unrealized holding gains or losses [Member]
Reclassification adjustment out of accumulated other comprehensive income
Non-operating income		0.0
Reclassification out of accumulated other comprehensive income [Member] \| Net gains realized on dispositions [Member]
Reclassification adjustment out of accumulated other comprehensive income
Provision for income taxes		0.0	18.6
Reclassification out of accumulated other comprehensive income [Member] \| Currency translation adjustments [Member]
Reclassification adjustment out of accumulated other comprehensive income
Non-operating income		(3.1)	0.0
Provision for income taxes		0.8	$ 0.0
Reclassification out of accumulated other comprehensive income [Member] \| Total accumulated other comprehensive income (loss) [Member]
Reclassification adjustment out of accumulated other comprehensive income
Non-operating income		(3.1)
Equity method investments [Member] \| Reclassification out of accumulated other comprehensive income [Member] \| Currency translation adjustments [Member]
Reclassification adjustment out of accumulated other comprehensive income
Non-operating income		0.0
Variable interest entities [Member] \| Reclassification out of accumulated other comprehensive income [Member] \| Currency translation adjustments [Member]
Reclassification adjustment out of accumulated other comprehensive income
Non-operating income		$ (3.1)