SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowance adjustment	$ 0	$ 0	$ 500,000
Allowance for doubtful accounts and sales returns and allowances
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	6,194,000	7,221,000	6,978,000
Charged to Costs and Expenses	1,944,000	601,000	1,315,000
Charged to Other Accounts	0	0	0
Deductions	(1,954,000)	(1,628,000)	(1,072,000)
Balance at End of Period	6,184,000	6,194,000	7,221,000
Deferred tax asset valuation allowance (As adjusted)
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	9,060,000	14,243,000	32,304,000
Charged to Costs and Expenses	(1,102,000)	(4,469,000)	(16,979,000)
Charged to Other Accounts	0	0	477,000
Deductions	(698,000)	(714,000)	(1,559,000)
Balance at End of Period	$ 7,260,000	$ 9,060,000	$ 14,243,000