New Accounting Standards New Accounting Standards Adopted (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017	Dec. 31, 2017	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle
Change in net cash used in investing activities	$ (11,102)	$ (14,973)
Change in net cash provided by operating activities	68,711	42,120
Change in cash, cash equivalents and restricted cash	$ 242,268	265,905	$ 212,824	$ 275,949
Restricted cash guidance
New Accounting Pronouncements or Change in Accounting Principle
Change in net cash used in investing activities		(8,545)
Change in net cash provided by operating activities		3,468
Change in cash, cash equivalents and restricted cash		$ 72,670		$ 77,709