Schedule II - Valuation and Qualifying Accounts (Details) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 45,516	$ 57,980	$ 69,939
Additions: Charges to expense	6,873	4,312	8,453
Deductions	(42,417)	(11,737)	(13,185)
Other changes	(2,373)	(5,039)	(7,227)
Balance at end of period	$ 7,599	$ 45,516	$ 57,980