Stock-Based Compensation - Summary of Stock Options Outstanding and Exercisable (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares Under Options, Outstanding at January 1, 2014	1,201,753
Shares Under Options, Granted	176,000	173,750	164,500
Shares Under Options, Exercised	(40,084)
Shares Under Options, Forfeited	(135,500)
Shares Under Options, Outstanding at December 31, 2014	1,202,169	1,201,753
Shares Under Options, Exercisable at December 31, 2014	914,752
Shares Under Options, Vested or expected to vest at December 31, 2014	1,197,365
Weighted Average Exercise Price, Outstanding at January 1, 2014	$ 24.85
Weighted Average Exercise Price, Granted	$ 20.00	$ 17.16	$ 17.67
Weighted Average Exercise Price, Exercised	$ 14.50
Weighted Average Exercise Price, Forfeited	$ 26.87
Weighted Average Exercise Price, Outstanding at December 31, 2014	$ 24.25	$ 24.85
Weighted Average Exercise Price, Exercisable at December 31, 2014	$ 25.97
Weighted Average Exercise Price, Vested or expected to vest at December 31, 2014	$ 24.27
Remaining Contractual Life In Years, Outstanding at December 31, 2014	6 years	6 years 6 months
Stock options life, years	6 years	6 years 6 months
Remaining Contractual Life In Years, Exercisable at December 31, 2014	5 years 2 months 12 days
Remaining Contractual Life In Years, Vested or expected to vest at December 31, 2014	6 years
Intrinsic Value, Outstanding at January 1, 2014	$ 982
Intrinsic Value, Outstanding at December 31, 2014	778	982
Intrinsic Value, Exercisable at December 31, 2014	778
Intrinsic Value, Vested or expected to vest at December 31, 2014	$ 778