Summary of Options Outstanding (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options outstanding	2,034
Options outstanding, Weighted average remaining life in years	4 years 7 months
Options outstanding, Weighted-average exercise price	$ 9.67
Number of Options exercisable	728
Options exercisable, Weighted average exercise price	$ 7.92
Range One
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum	$ 0.00
Range of exercise prices, maximum	$ 9.40
Number of Options outstanding	842
Options outstanding, Weighted average remaining life in years	3 years 0 months
Options outstanding, Weighted-average exercise price	$ 7.96
Number of Options exercisable	602
Options exercisable, Weighted average exercise price	$ 7.50
Range Two
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum	$ 9.88
Range of exercise prices, maximum	$ 9.88
Number of Options outstanding	541
Options outstanding, Weighted average remaining life in years	5 years 1 month
Options outstanding, Weighted-average exercise price	$ 9.88
Number of Options exercisable	126
Options exercisable, Weighted average exercise price	$ 9.88
Range Three
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, minimum	$ 11.71
Range of exercise prices, maximum	$ 11.71
Number of Options outstanding	651
Options outstanding, Weighted average remaining life in years	6 years 1 month
Options outstanding, Weighted-average exercise price	$ 11.71
Number of Options exercisable	0
Options exercisable, Weighted average exercise price	$ 0.00