Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 25, 2016
Deferred tax assets
Accrued liabilities	$ 11,378	$ 14,479
Accrued bonuses	192	5,399
Other assets and liabilities	7,913	12,434
Equity awards	5,690	7,704
Other	2,178	3,716
Foreign net operating losses	2,773	3,418
Foreign tax credit carryforwards	4,707	2,347
Total deferred tax assets	34,831	49,497
Valuation allowance on foreign net operating and capital losses, foreign deferred tax assets, and foreign tax credit carryforwards	(7,415)	(5,462)
Total deferred tax assets, net of valuation allowances	27,416	44,035
Deferred tax liabilities
Deferred expenses	(6,912)	(9,544)
Accelerated depreciation	(19,228)	(25,072)
Goodwill	(12,248)	(18,480)
Other	(989)	(217)
Total deferred tax liabilities	(39,377)	(53,313)
Net deferred liability	$ (11,961)	(9,278)
Other tax disclosures
Expiration term of foreign tax credit carryforwards	10 years
Foreign tax authority
Other tax disclosures
Net operating loss carryovers	$ 9,400	14,500
Valuation allowance related to net operating losses	2,100	$ 3,100
Foreign tax credit carryforwards
Deferred tax assets
Valuation allowance on foreign net operating and capital losses, foreign deferred tax assets, and foreign tax credit carryforwards	$ (4,700)