Equity - Stock Repurchase Activities (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accelerated Share Repurchases [Line Items]
Common stock received, aggregate price	$ 131.9	$ 243.2
Stock Repurchase Program 2018
Accelerated Share Repurchases [Line Items]
Stock repurchased (in shares)	5.1
Common stock received, aggregate price	$ 125.0	$ 200.0
Common stock repurchased, average cost per share (in dollars per share)	$ 24.45
Stock repurchase program, remaining authorized repurchase amount	$ 1,200.0