Annual report pursuant to Section 13 and 15(d)

Compensation and Other Benefit Plans - Unvested RSU Activity (Details)

v3.8.0.1
Compensation and Other Benefit Plans - Unvested RSU Activity (Details) - Restricted Stock Units (RSUs) [Member]
12 Months Ended
Dec. 31, 2017
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Number of Shares, Unvested balance at January 1, 2017 | shares 91,228
Number of Shares, Granted | shares 11,799
Number of Shares, Vested | shares (62,405)
Number of Shares, Forfeited | shares (22,142)
Number of Shares, Unvested balance at December 31, 2017 | shares 18,480
Weighted-Average Grant-Date Fair Value, Unvested balance at January 1, 2017 | $ / shares $ 39.82
Weighted-Average Grant-Date Fair Value, Granted | $ / shares 4.67
Weighted-Average Grant-Date Fair Value, Vested | $ / shares 37.63
Weighted-Average Grant-Date Fair Value, Forfeited | $ / shares 45.45
Weighted-Average Grant-Date Fair Value, Unvested balance at December 31, 2017 | $ / shares $ 18.00