Stock Option Plan - Vested or Expected to Vest (Details) - USD ($)
11 Months Ended 12 Months Ended
Dec. 31, 2014
Dec. 31, 2016
Dec. 31, 2015
Options outstanding and exercisable      
Vested, Number of Shares (in shares)   397,486  
Vested, Weighted Average Exercise Price (in dollars per share)   $ 8.02  
Vested, Weighted Average Remaining Contractual Life   8 years 10 months 2 days  
Vested, Aggregate Intrinsic Value   $ 2,660,000  
Expected to vest, Number of Shares (in shares)   1,953,096  
Expected to vest, Weighted Average Exercise Price (in dollars per share)   $ 12.66  
Expected to vest, Weighted Average Remaining Contractual Life   9 years 3 months 7 days  
Expected to vest, Aggregate Intrinsic Value   $ 4,869,000  
Fair value of common stock (in dollars per share)   $ 14.30  
Aggregate intrinsic value of stock options exercised $ 0 $ 216,000 $ 714,000
Fair value of options vested $ 100 $ 3,195,000 $ 75,000