XML 99 R89.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation - Summary of Vested and Unvested Restricted Stock Units Outstanding (Details) - Restricted Stock Units (RSUs) - $ / shares
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Restricted Stock Units Outstanding, Balance, beginning of period (unvested) 1,214,325 1,200,848
Restricted Stock Units Outstanding, Grants 105,429 73,801
Restricted Stock Units Outstanding, Released and distributed (vested) (170,160) (70,687)
Restricted Stock Units Outstanding, Forfeited/expired (5,556) (544)
Restricted Stock Units Outstanding, Balance, end of period (unvested) 1,144,038 1,203,418
Weighted Average Grant Date Fair Value, Balance, beginning of period (unvested) $ 19.97 $ 19.00
Weighted Average Grant Date Fair Value, Grants 39.90 33.48
Weighted Average Grant Date Fair Value, Released and distributed (vested) 21.24 19.00
Weighted Average Grant Date Fair Value, Forfeited/expired 19.00 19.00
Weighted Average Grant Date Fair Value, Balance, end of period (unvested) $ 21.11 $ 19.15