Schedule II: Valuation and Qualifying Accounts (Details) - 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	$ 89,004	$ 268	$ 1,020
Charged (credited) to expense	8,621	88,741	(337)
Deductions from reserves	(1,990)	(5)	(415)
Balance at end of period	95,635	89,004	268
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	267	268	332
Charged (credited) to expense	(20)	4	113
Deductions from reserves	(24)	(5)	(177)
Balance at end of period	223	267	268
Allowance for Notes Receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		0	688
Charged (credited) to expense			(450)
Deductions from reserves			(238)
Balance at end of period			0
Valuation Allowance on Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	88,737	0
Charged (credited) to expense	8,641	88,737
Deductions from reserves	(1,966)	0
Balance at end of period	$ 95,412	$ 88,737	$ 0