Share-Based Compensation - Summary of Option Activity (Detail) - Option Activity Under the 2003 Plan [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Schedule Of Stock Option Activity [Line Items]
Option outstanding, Shares, Beginning balance | shares	77,947
Option granted, Shares | shares	0
Option Exercised, Shares | shares	(33,347)
Option forfeited, Shares | shares	(600)
Option outstanding, Shares, Ending balance | shares	44,000
Option Exercisable, Shares, Ending balance | shares	41,750
Option outstanding, Weighted Average Exercise Price, Beginning balance | $ / shares	$ 11.35
Option Granted, Weighted Average Exercise Price | $ / shares	0
Option Exercised, Weighted Average Exercise Price | $ / shares	11.63
Option Forfeited, Weighted Average Exercise Price | $ / shares	16.46
Option Outstanding, Weighted Average Exercise Price, Ending balance | $ / shares	11.07
Option Exercisable, Weighted Average Exercise Price, Ending balance | $ / shares	$ 10.85
Option Outstanding, Weighted Average Remaining Contractual Term	4 years 7 days
Option Exercisable, Weighted Average Remaining Contractual Term	3 years 10 months 24 days
Option outstanding, Aggregate Intrinsic Value | $	$ 743,164
Option Exercisable, Aggregate Intrinsic Value | $	$ 714,286