Schedule II - Valuation and Qualifying Accoutns (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Period Increase (Decrease)	$ 8,126	$ (338)	$ (5,396)
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance Period Start	58,277	58,615	64,011
Deductions	0	0	0
Valuation Allowances and Reserves, Balance Period End	66,403	58,277	58,615
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Additions for Charges to Cost and Expense	3,785	8,783	7,164
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance Period Start	24,418	27,973	32,471
Deductions	(4,836)	(12,338)	(11,662)
Valuation Allowances and Reserves, Balance Period End	$ 23,367	$ 24,418	$ 27,973