Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Accounts Receivable Allowances [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 16,815	$ 13,485	$ 12,860
Additions charged to operating costs and other	11,747	17,154	13,999
Deductions	14,020	13,824	13,374
Balance at end of period	14,542	16,815	13,485
Valuation Allowance for Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	0	36,204	41,136
Additions charged to operating costs and other	0	0	0
Deductions	0	36,204	4,932
Balance at end of period	$ 0	$ 0	$ 36,204