Earnings Per Share (Calculation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Income from continuing operations, net of taxes	$ 1,161.0	$ 868.3	$ 964.1
Net (income)/loss attributable to noncontrolling interests in consolidated entities	(33.7)	(14.1)	4.0
Net income attributable to Invesco Ltd. for basic and diluted EPS calculations	1,127.3	854.2	968.1
Net income attributable to Invesco Ltd.	1,127.3	854.2	968.1
Allocation of earnings to restricted shares	(33.7)	(24.8)	(24.6)
Net income attributable to common shareholders	$ 1,093.6	$ 829.4	$ 943.5
Weighted average shares outstanding - basic (in shares)	409.4	414.7	428.9
Weighted Average Number of Shares, Restricted Stock	(12.2)	(12.1)	(10.9)
Weighted Average Number of Shares Outstanding, Basic - Common shareholders	397.2	402.6	418.0
Dilutive effect on share-based awards (in shares)	0.5	0.3	0.4
Weighted Average Number of Shares Outstanding, Diluted - Common shares	397.7	402.9	418.4
Weighted average shares outstanding - diluted (in shares)	409.9	415.0	429.3
Earnings per share:
Basic earnings per share (usd per share)	$ 2.75	$ 2.06	$ 2.26
Diluted earnings per share:
Diluted earnings per share (usd per share)	$ 2.75	$ 2.06	$ 2.26