Employee Benefit Plans - Restricted Stock Unit and Performance Share Award Activities (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) $ / shares shares
Service-based RSUs
Number of Shares
Granted (in shares)	1.4
RSUs, RSAs, and PSAs
Number of Shares
Balance at beginning of period (in shares)	17.5
Granted (in shares)	2.6
Vested (in shares)	(4.2)
Canceled (in shares)	(1.0)
Balance at end of period (in shares)	14.9
Weighted Average Grant-Date Fair Value per Share
Balance at beginning of period (in dollars per share) | $ / shares	$ 25.30
Granted (in dollars per share) | $ / shares	22.80
Vested (in dollars per share) | $ / shares	26.01
Canceled (in dollars per share) | $ / shares	25.78
Balance at end of period (in dollars per share) | $ / shares	$ 24.62
Weighted average remaining contractual term	1 year 3 months 18 days
Aggregate intrinsic value | $	$ 284.5
Performance Shares
Number of Shares
Granted (in shares)	0.8
Market-based RSUs
Number of Shares
Granted (in shares)	0.4