Employee Benefit Plans, Share Based Compensation, Equity Instruments Other Than Options (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended
	Jun. 23, 2015	Jun. 30, 2015	Jun. 30, 2014
Weighted Average Grant-Date Fair Value per Share
Common stock, dividends paid per share (in dollar per share)	$ 0.1
Common stock dividends paid	$ 38.8	$ 79.5
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		1,400,000	1,500,000
Average price of common stock, per share		$ 19.32	$ 18.67
RSUs, RSAs, and PSAs [Member]
Number of Shares
Balance as of December 31, 2014 (in shares)		21,300,000
Balance as of June 30, 2015 (in shares)		20,200,000
Weighted Average Grant-Date Fair Value per Share
Balance as of December 31, 2014 (in dollars per share)		$ 22.05
Balance as of June 30, 2015 (in dollars per share)		$ 21.94
Weighted Average Remaining Contractual Term (In Years)		1 year 4 months 24 days
Aggregate Intrinsic Value		$ 524.7
Restricted stock units (RSUs)
Number of Shares
Granted (in shares)		7,300,000
Vested (in shares)		(5,400,000)
Canceled (in shares)		(1,600,000)
Weighted Average Grant-Date Fair Value per Share
Granted (in dollars per share)		$ 22.63
Vested (in dollars per share)		23.47
Canceled (in dollars per share)		$ 22.00
Performance shares (PSAs)
Number of Shares
Granted (in shares)		800,000
Vested (in shares)		(200,000)
Canceled (in shares)		(1,000,000)
Weighted Average Grant-Date Fair Value per Share
Granted (in dollars per share)		$ 22.44
Vested (in dollars per share)		22.65
Canceled (in dollars per share)		$ 22.28
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		800,000
Restricted stock awards (RSAs)
Number of Shares
Vested (in shares)		(1,000,000)
Weighted Average Grant-Date Fair Value per Share
Vested (in dollars per share)		$ 20.51