Stock Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Award Activity

Award activity — (shares in millions)

	Options				SARs				RSUs				PSUs
			Weighted- Average				Weighted- Average				Weighted- Average Grant-Date			Weighted- Average Grant-Date
Outstanding at	Shares		Exercise Price		Shares		Exercise Price		Shares		Fair Value		Shares	Fair Value
December 31, 2013	2.6		$	13.85	0.5		$	15.46	1.3		$	16.29	—	$	—
Granted									0.7		21.20		0.3	24.36
Exercised or vested	(0.6	)	11.48		(0.1	)	16.49		(0.4	)	16.99
Forfeited or expired	(0.1	)	15.89						(0.1	)	14.91
December 31, 2014	1.9		$	14.46	0.4		$	15.18	1.5		$	18.18	0.3	$	24.36

	2014		2013		2012
Weighted-average per share grant-date fair value
Stock options	N/A		$	7.46	$	7.88
SARs	N/A		7.45		7.84
Intrinsic value of awards exercised or vested
Stock options / SARs	$	7	$	14	$	18
RSUs / PSUs	8		5		11

Key Assumptions as Part of Black-Scholes Option Pricing Model

We estimated fair values for options and SARs at the date of grant using the following key assumptions as part of the Black-Scholes option pricing model. The expected term was estimated using the simplified method because the limited period of time our common stock had been publicly traded provided insufficient historical exercise data. The risk-free rate was based on U.S. Treasury security yields at the time of grant. The dividend yield was calculated by dividing the expected annual dividend by the average stock price of our common stock over the prior year. The expected volatility was estimated using a combination of the historical volatility of similar entities and the implied volatility of our exchange-traded options.

	Options				SARs
	2013		2012		2013		2012
Expected term (in years)	6.00		6.00		6.00		6.00
Risk-free interest rate	1.07	%	1.24	%	1.07	%	1.24	%
Dividend yield	1.41	%	1.33	%	1.41	%	1.33	%
Expected volatility	55.80	%	59.90	%	55.80	%	59.90	%

Outstanding Awards Expected to Vest and Exercisable

Outstanding awards expected to vest and exercisable or convertible at December 31, 2014 — (shares in millions)

	Equity Awards Outstanding Expected to Vest						Equity Awards Outstanding That are Exercisable or Convertible
				Weighted-Average						Weighted-Average
	Shares	Aggregate Intrinsic Value		Exercise Price		Remaining Contractual Life in Years	Shares	Aggregate Intrinsic Value		Exercise Price		Remaining Contractual Life in Years
Options / SARs	2.3	$	16	$	14.56	6.9	1.4	$	12	$	13.64	6.3
RSUs / PSUs	1.8	39		—		1.3	0.1	1		—		0.2