Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Data (Unaudited)

	2016 Quarter Ended
(in millions, except per share amounts)	Dec. 31		Sept. 30		June 30		Mar. 31
Revenue	$	1,095	$	897	$	932	$	847
Gross profit	406		357		369		329
Operating income	109		109		109		79
Net income	$	50	$	73	$	71	$	66
Earnings per share:
Basic	$	0.28	$	0.41	$	0.39	$	0.37
Diluted	$	0.28	$	0.41	$	0.39	$	0.37

	2015 Quarter Ended
(in millions, except per share amounts)	Dec. 31		Sept. 30		June 30		Mar. 31
Revenue	$	994	$	902	$	920	$	837
Gross profit	390		351		348		315
Operating income	142		120		104		83
Net income	$	114	$	88	$	74	$	64
Earnings per share:
Basic	$	0.64	$	0.48	$	0.41	$	0.35
Diluted	$	0.63	$	0.48	$	0.41	$	0.35