Stock Incentive Plans - Summary of Activity Relating to Stock Options (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Options outstanding at beginning of period	435,340	568,834
Shares, Assumed from acquisitions	1,707,036
Shares, Exercised	(287,787)	(82,810)
Shares, Forfeited	(93,391)	(2,182)
Shares, Options outstanding and exercisable at end of period	1,761,198	483,842
Weighted Average Price per Share, Options outstanding at beginning of period	$ 8.86	$ 8.86
Weighted Average Price per Share, Assumed from acquisition	7.83
Weighted Average Price per Share, Exercised	7.11	5.57
Weighted Average Price per Share, Forfeited	6.73	4.34
Weighted Average Price per Share, Options outstanding and exercisable at end of period	$ 8.26	$ 9.44