Stockholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($)	6 Months Ended
	Jun. 25, 2017	Jun. 26, 2016	Dec. 25, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive loss	$ (1,500,000)	$ (1,500,000)	$ (1,700,000)
Reclassifications from other comprehensive income	0	0
Cumulative translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive loss	(900,000)	(700,000)
Post-retirement benefit reserve adjustment net of tax expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive loss	$ (600,000)	$ (800,000)