Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Additions Charged to Cost and Expenses	$ (4,604)	$ (13,289)	$ (14,595)
Income tax provision	(859)	(9,601)	(35,685)
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	42	673	417
Additions Charged to Cost and Expenses	0	134	855
Deductions	0	(765)	(599)
Balance at End of Year	42	42	673
Deferred tax asset valuation allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	13,644	33,889	19,294
Additions Charged to Cost and Expenses		13,289	14,595
Deductions		(33,534)	0
Balance at End of Year		$ 13,644	$ 33,889
Valuation Allowance, Operating Loss Carryforwards
Movement in Valuation Allowances and Reserves [Roll Forward]
Income tax provision	$ 355