Other Financial Information - Narrative (Details)	3 Months Ended
	Mar. 31, 2019 USD ($)
Other Financial Information [Abstract]
Contract manufacturer deposit (non-interest bearing)	$ 47,600,000
Non-interest bearing deposit to contract manufacturer, unamortized discount	$ 2,300,000
Non-interest bearing deposit to contract manufacturer, imputed interest rate	4.80%
Deferred commission	$ 26,100,000
Amortization of deferred commission	34,900,000
Impairment loss	$ 0