Employee Benefits - Additional Information (Detail) (401 (k) retirement plan, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Cost of employer contributions to the plan	$ 2,488	$ 1,908	$ 1,624
Defined contribution plan, matching employer contribution percentage	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	6.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employees contribution percentage	1.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employees contribution percentage	100.00%