Earnings per Share - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Basic:
Net income	$ 70	$ 17	$ 179	$ 25
Weighted-average shares outstanding (in shares)	53,537,876	51,996,353	53,414,267	51,928,911
Basic earnings per share (USD per share)	$ 1.31	$ 0.33	$ 3.35	$ 0.49
Diluted:
Net income	$ 70	$ 17	$ 179	$ 25
Weighted-average shares outstanding (in shares)	53,537,876	51,996,353	53,414,267	51,928,911
Dilutive shares (in shares)	717,831	1,132,304	719,843	1,109,045
Diluted weighted-average shares outstanding (in shares)	54,255,707	53,128,657	54,134,110	53,037,956
Diluted earnings per share (USD per share)	$ 1.29	$ 0.32	$ 3.30	$ 0.48