Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

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)	2018		2017
Restricted stock unit awards	$	10	$	8
Performance awards	7		7
Pretax stock-based compensation cost	$	17	$	15
Tax benefit associated with stock-based compensation expense	$	4	$	5
Stock-based compensation costs capitalized	1		1