Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

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

Schedule Of Stock-Based Compensation Expense

Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense and stock-based compensation costs capitalized are included in the following table.

	Three Months Ended
	March 31,
(in millions)	2017		2016
Restricted stock unit awards	$	8	$	7
Performance awards	7		5
Pretax stock-based compensation cost	$	15	$	12
Tax benefit associated with stock-based compensation expense	$	5	$	4
Stock-based compensation costs capitalized	1		1