Employee Benefit Plans - Narrative (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) SERP_retirement_age	Dec. 31, 2015 USD ($) year	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Compensation and Retirement Disclosure [Abstract]
Employers matching contribution			50.00%
Employees first contribution			6.00%
401(k) profit sharing plan, employers matching contribution amount		$ 1,100,000				$ 1,000,000	$ 600,000
SERP annual retirement benefits period (years)	15 years
SERP retirement age				65	65
SERP target annual retirement benefit	$ 300,000	300,000	$ 300,000	$ 300,000	$ 300,000
SERP annual rate of return			7.00%
SERP present value of the amount owed	$ 3,600,000	$ 3,600,000	$ 3,600,000	$ 3,600,000	$ 3,600,000