Fair Value Measurements Impairment Long-lived Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014
Fair Value Disclosures [Abstract]
Impairment of Long-Lived Assets Held-for-use	$ 3,730	$ 487	$ 4,677	$ 568