Stock Plans and Other Incentives - Option Activity and Other Plan Data (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding at beginning of period, Options	547,500	582,500
Granted, Options	0	0
Exercised, Options	(17,500)	(7,500)
Forfeited/cancelled/expired, Options	0	0
Outstanding at end of period, Options	530,000	575,000
Options exercisable at end of period, Options	518,000	559,000
Outstanding at beginning of period, Weighted-Average Exercise Price	$ 9.61	$ 9.52
Granted, Weighted-Average Exercise Price	0	0
Exercised, Weighted-Average Exercise Price	(8.74)	(7.50)
Forfeited/cancelled/expired, Weighted-Average Exercise Price	0	0
Outstanding at end of period, Weighted-Average Exercise Price	9.64	9.55
Options exercisable at end of period, Weighted-Average Exercise Price	$ 9.44	$ 9.29