Stock Incentive Plans - Summary of Information Concerning Stock Option Awards (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 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	(24,806)	(60,094)
Shares, Forfeited	(92,650)	(2,182)
Shares, Options outstanding and exercisable at end of period	2,024,920	506,558
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	6.38	5.04
Weighted Average Price per Share, Forfeited	6.69	4.34
Weighted Average Price per Share, Options outstanding and exercisable at end of period	$ 8.12	$ 9.33