Income Taxes - Schedule of Effective Income Tax Rates Varied from Statutory Federal Income Tax Rate (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax provision based on the federal statutory rate, Amount	$ 68,070	$ 69,128	$ 62,172
State and local income taxes—net of federal income tax benefit, Amount	4,816	5,292	3,464
Change in tax reserves and accrual adjustments, Amount	(115)	(69)	(521)
Non-deductible and other, Amount	2,514	(11)	690
Provision for income taxes	$ 75,285	$ 74,340	$ 65,805
% of Pre-tax Income of Tax provision based on the federal statutory rate	35.00%	35.00%	35.00%
% of Pre-tax Income of State and local income taxes-net of federal income tax benefit	2.50%	2.60%	2.00%
% of Pre-tax Income of Change in tax reserves and accrual adjustments	(0.10%)	0.00%	(0.40%)
% of Pre-tax Income of Non-deductible and other	1.30%	0.00%	0.40%
% of Pre-tax Income of Provision for income taxes	38.70%	37.60%	37.00%