Employee Benefit Plans, Share Based Compensation, Equity Instruments Other Than Options (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended
	Mar. 22, 2016	Jun. 30, 2016	Jun. 30, 2015
Weighted Average Grant-Date Fair Value per Share
Common stock, dividends paid per share (in dollars per share)	$ 0.1
Common stock dividends paid	$ 38.1	$ 76.4
Employee stock purchase plan 2008 [Member]
Employee Stock Purchase Plan
Employee stock purchase plans offering period duration		6 months
Stock issued during period, shares, employee stock purchase plans		1,300,000	1,400,000
Average price of common stock, per share (in dollars per share)		$ 20.06	$ 19.32
RSUs, RSAs, and PSAs [Member]
Number of Shares
Balance at beginning of period (in shares)		18,600,000
Balance at end of period (in shares)		18,600,000
Weighted Average Grant-Date Fair Value per Share
Balance at beginning of period (in dollars per share)		$ 22.71
Balance at end of period (in dollars per share)		$ 23.73
Weighted Average Remaining Contractual Term (In Years)		1 year 4 months 24 days
Aggregate Intrinsic Value		$ 419.3
Restricted Stock Units (RSUs) [Member]
Number of Shares
Granted (in shares)		6,900,000
Assumed (in shares)		200,000
Vested (in shares)		(5,500,000)
Canceled (in shares)		(700,000)
Weighted Average Grant-Date Fair Value per Share
Granted (in dollars per share)		$ 24.68
Assumed (in dollars per share)		24.76
Vested (in dollars per share)		22.37
Canceled (in dollars per share)		$ 23.15
Performance shares (PSAs)
Number of Shares
Granted (in shares)		700,000
Assumed (in shares)		200,000
Vested (in shares)		(600,000)
Canceled (in shares)		(400,000)
Weighted Average Grant-Date Fair Value per Share
Granted (in dollars per share)		$ 23.62
Assumed (in dollars per share)		25.09
Vested (in dollars per share)		21.61
Canceled (in dollars per share)		$ 21.81
Aggregate number of shares subject to PSAs granted		500,000
Minimum shares to be issued on achievement of performance goals in respect of PSAs		0
Maximum shares to be issued on achievement of performance goals in respect of PSAs		700,000
Restricted stock awards (RSAs)
Number of Shares
Vested (in shares)		(800,000)
Weighted Average Grant-Date Fair Value per Share
Vested (in dollars per share)		$ 20.76