Stock Plans and Other Incentives - Option Activity and Other Plan Data (Detail) (USD $)	1 Months Ended	9 Months Ended
	May 31, 2014	Sep. 30, 2014	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding at beginning of period, Options		627,724	645,448
Granted, Options	20,000	20,000
Exercised, Options		(35,000)
Cancelled through cash settlement, Options		(8,862)
Forfeited/cancelled/expired, Options
Outstanding at end of period, Options		603,862	645,448
Options exercisable at end of period, Options		583,862	645,448
Options exercisable which can be settled in cash, Options		8,862	35,448
Outstanding at beginning of period, Weighted-Average Exercise Price		$ 9.05	$ 8.94
Granted, Weighted-Average Exercise Price	$ 18.52	$ 18.52
Exercised, Weighted-Average Exercise Price		$ (9.57)
Cancelled through cash settlement, Weighted-Average Exercise Price		$ (4.09)
Forfeited/cancelled/expired, Weighted-Average Exercise Price
Outstanding at end of period, Weighted-Average Exercise Price		$ 9.40	$ 8.94
Options exercisable at end of period, Weighted-Average Exercise Price		$ 9.09	$ 8.94
Options exercisable which can be settled in cash, Weighted-Average Exercise Price		$ 4.09	$ 4.67