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
Valuation and Qualifying Accounts
Balance at Beginning of Period	$ 10,191	$ 5,200	$ 2,233
Charged (Credited) to Costs and Expenses	25,342	4,366	3,141
Charged to Other Accounts	325	625
Deductions	(218)		(174)
Balance at End of Period	35,640	10,191	5,200
Allowance for doubtful accounts
Valuation and Qualifying Accounts
Balance at Beginning of Period	2,438	492	468
Charged (Credited) to Costs and Expenses	(1,814)	1,946	198
Charged to Other Accounts	325
Deductions	(218)		(174)
Balance at End of Period	731	2,438	492
Valuation allowance in net deferred tax assets
Valuation and Qualifying Accounts
Balance at Beginning of Period	7,753	4,708	1,765
Charged (Credited) to Costs and Expenses	27,156	2,420	2,943
Charged to Other Accounts		625
Balance at End of Period	$ 34,909	$ 7,753	$ 4,708