EARNINGS PER COMMON SHARE - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income attributable to Invesco Ltd.	$ 330.1	$ 191.7	$ 966.2	$ 313.7
Weighted average shares outstanding - basic (shares)	463.3	461.1	462.6	459.0
Dilutive effect of non-participating common share-based awards (shares)	2.7	2.4	3.0	3.0
Weighted average shares outstanding - diluted (shares)	466.0	463.5	465.6	462.0
Earnings per common share:
- basic (usd per share)	$ 0.71	$ 0.42	$ 2.09	$ 0.68
- diluted (usd per share)	$ 0.71	$ 0.41	$ 2.08	$ 0.68