CONSOLIDATED T. ROWE PRICE INVESTMENT PRODUCTS. (Statement of Cash Flows) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	$ 1,918.9	$ 1,522.7	$ 1,619.9
Net cash provided by (used in) investing activities	(36.3)	(324.5)	(875.5)
Net cash used in financing activities	(1,486.3)	(832.7)	(1,239.5)
FX impact on cash	1.9	(2.5)	(15.4)
Net change in cash and cash equivalents during period	398.2	363.0	(510.5)
Cash and cash equivalents at beginning of year	1,858.3	1,495.3	2,005.8
Cash and cash equivalents at end of year	2,256.5	1,858.3	1,495.3
Consolidation eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash used in financing activities	79.5	174.4	84.9
Consolidated T. Rowe Price investment products
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents at beginning of year	76.5	70.1	103.1
Cash and cash equivalents at end of year	104.8	76.5	70.1
Consolidated T. Rowe Price investment products \| Reportable entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	(556.7)	(670.8)	(549.1)
Net cash provided by (used in) investing activities	(53.9)	(18.4)	(23.8)
Net cash used in financing activities	637.0	698.1	555.3
FX impact on cash	1.9	(2.5)	(15.4)
Net change in cash and cash equivalents during period	28.3	6.4	(33.0)
Cash and cash equivalents at beginning of year	76.5	70.1	103.1
Cash and cash equivalents at end of year	104.8	76.5	70.1
VOE \| Reportable entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	(155.4)	(7.2)	(43.9)
Net cash provided by (used in) investing activities	(23.4)	(7.1)	(0.8)
Net cash used in financing activities	176.0	5.7	56.1
FX impact on cash	0.0	0.0	0.0
Net change in cash and cash equivalents during period	(2.8)	(8.6)	11.4
Cash and cash equivalents at beginning of year	9.9	18.5	7.1
Cash and cash equivalents at end of year	7.1	9.9	18.5
VIE \| Reportable entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	(401.3)	(663.6)	(505.2)
Net cash provided by (used in) investing activities	(30.5)	(11.3)	(23.0)
Net cash used in financing activities	461.0	692.4	499.2
FX impact on cash	1.9	(2.5)	(15.4)
Net change in cash and cash equivalents during period	31.1	15.0	(44.4)
Cash and cash equivalents at beginning of year	66.6	51.6	96.0
Cash and cash equivalents at end of year	$ 97.7	$ 66.6	$ 51.6

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