Debt (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended		12 Months Ended
	Jun. 30, 2016	Nov. 30, 2015	Oct. 31, 2015	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Interest expense				$ 183	$ 115
Secured Loan Arrangement
Debt Instrument [Line Items]
Exercise price of warrants (in dollars per share)				$ 2.3229
Line Of Credit-UBS
Debt Instrument [Line Items]
Borrowing capacity							$ 50,000
Borrowings	$ 8,000	$ 10,000	$ 32,000
Repayments	$ 1,000
Outstanding balance		$ 42,000		$ 49,800		$ 49,000
Accrued interest				$ 200		$ 600
Line Of Credit-UBS | 30-day LIBOR
Debt Instrument [Line Items]
Spread on variable rate (as a percent)				0.65%