Changes in the Shares of Common Stock Outstanding (Detail) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Stockholders Equity Note [Abstract]
Beginning balance	29,386,882	28,891,766
Restricted common stock awards granted, net of forfeitures	391,003	460,064
Restricted stock units converted to common stock	6,840
Common stock options exercised	750	27,500
Warrants exercised, net of repurchases		7,552
Ending balance	29,785,475	29,386,882