Schedule II - Valuation and Qualifying Accounts (Details) (Allowance for doubtful accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Jan. 01, 2012
Allowance for doubtful accounts
Valuation and Qualifying Accounts
Balance at Beginning of Period	$ 2,546	$ 2,426	$ 1,281
Charged to Cost and Expenses	1,136	757	1,812
Charged to Other Accounts	0	(1)	3
Deductions, Actual Charge-Offs	(1,133)	(635)	(670)
Balance at End of Period	$ 2,549	$ 2,546	$ 2,426