Stock Options Outstanding (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Options Outstanding
Options Outstanding, beginning balance	2,343,000	3,427,000	4,322,000
Options Outstanding, options granted	0	0	0
Options Outstanding, options exercised	(6,000)	(317,000)	(289,000)
Options Outstanding, options forfeited	(434,000)	(767,000)	(606,000)
Options Outstanding, ending balance	1,902,267	2,343,000	3,427,000
Weighted-Average Exercise Price
Weighted-average exercise price, beginning balance	$ 14.24	$ 14.35	$ 14.28
Weighted-average exercise price, Options granted	0.00	0.00	0.00
Weighted-average exercise price, options exercised	14.01	11.44	11.88
Weighted-average exercise price, options forfeited	15.51	15.89	15.03
Weighted-average exercise price, ending balance	$ 13.95	$ 14.24	$ 14.35
Options Exercisable
Options Exercisable	1,431,288	1,282,000	1,393,000	1,025,000
Weighted-average exercise price, exercisable	$ 13.98	$ 14.52	$ 14.97	$ 15.52