Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Bad Debts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 1,384	$ 1,203	$ 1,183
Charged to costs and expenses	517	421	530
Charged to other accounts	0	0	0
Deductions	(662)	(240)	(510)
Balance at end of period	1,239	1,384	1,203
Sales Returns and Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	3,098	3,609	4,097
Charged to costs and expenses	252	398	317
Charged to other accounts	0	0	0
Deductions	(269)	(909)	(805)
Balance at end of period	3,081	3,098	3,609
Deferred Tax Asset Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	0	0	0
Charged to costs and expenses	293	0	0
Charged to other accounts	0	0	0
Deductions	0	0	0
Balance at end of period	$ 293	$ 0	$ 0