UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Cash and cash equivalents at beginning of period	$ 1,495.3	$ 1,766.2	$ 2,005.8
Cash and cash equivalents at end of period	1,733.5	1,495.3	1,766.2
Consolidated T. Rowe Price investment products [Member]
Cash and cash equivalents at beginning of period	70.1	84.8	103.1
Cash and cash equivalents at end of period	$ 76.1	$ 70.1	$ 84.8

Cash and Cash Equivalents, at Carrying Value, Including Consolidated Sponsored Investment Portfolios

No definition available.

Name:	trow_CashandCashEquivalentsatCarryingValueIncludingConsolidatedSponsoredInvestmentPortfolios
Namespace Prefix:	trow_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant