Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2015

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

Schedule of Market Performance Unit Award Valuation Assumptions



	2015 RTSR PSU
Weighted average grant date fair value	$	41.08
Weighted average expected volatility	25.1		%
Weighted average volatility of XHB	21.1		%
Weighted average correlation coefficient	0.57
Weighted average risk-free interest rate	1.0		%
Weighted average dividend yield	—

Schedule of Nonvested Share Activity

A summary of restricted stock, restricted stock unit and performance share unit activities for the nine months ended September 30, 2015 is presented below (number of shares in millions):



	Restricted Stock	Weighted Average Grant Date Fair Value		Restricted Stock Units		Weighted Average Grant Date Fair Value		Performance Share Units (b)	Weighted Average Grant Date Fair Value
Unvested at January 1, 2015	0.09	$	27.14	0.74		$	45.83	0.37	$	46.63
Granted	—	—		0.62		46.52		0.43	44.69
Vested (a)	—	—		(0.30	)	45.83		—	—
Forfeited	—	—		(0.02	)	46.24		—	—
Unvested at September 30, 2015	0.09	$	27.14	1.04		$	46.21	0.80	$	45.59

______________


(a)	The total fair value of restricted stock units which vested during the nine months ended September 30, 2015 was $14 million.


(b)	The PSU amounts in the table are shown at the target amount of the award.

Summary of Stock Options Valuation Assumptions



	2015 Options
Weighted average grant date fair value	$	17.66
Weighted average expected volatility	36.1		%
Weighted average expected term (years)	6.25
Weighted average risk-free interest rate	1.6		%
Weighted average dividend yield	—

Summary of Stock Options Activity

A summary of stock option unit activity for the nine months ended September 30, 2015 is presented below (number of shares in millions):



	Options		Weighted Average Exercise Price
Outstanding at January 1, 2015	3.22		$	30.02
Granted	0.18		46.45
Exercised (a) (b)	(0.16	)	21.31
Forfeited/Expired	(0.03	)	34.33
Outstanding at September 30, 2015 (c)	3.21		$	31.31

______________


(a)	The intrinsic value of options exercised during the nine months ended September 30, 2015 was $4 million.


(b)	Cash received from options exercised during the nine months ended September 30, 2015 was $3 million.


(c)	Options outstanding at September 30, 2015 have an intrinsic value of $34 million and have a weighted average remaining contractual life of 6.9 years.