Significant Accounting Policies Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	$ 36,188	$ 8,100	$ 36,188	$ 8,100	$ 30,445	$ 26,157	$ 0	$ 0
Deferred Revenue, Additions	8,772	8,276	15,114	8,276
Deferred Revenue, Revenue Recognized	(3,029)	$ (176)	(5,083)	$ (176)
Deferred Revenue, Current	14,678		14,678
Deferred Revenue, Noncurrent	$ 21,510		$ 21,510