Income Taxes (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Reduction in taxes payable as result of exercise and vesting of equity based compensation	$ (8,369)	$ (11,090)	$ (8,781)
Excess tax benefit associated with equity based compensation	2,069	7,518	3,765
Increase (decrease) to tax expense	(3,869)	1,220
Additional Increase to tax expense	15,546
Repayment of debt	1,429,195	525,909	493,560
Unrecognized tax benefits	0	0	$ 0
Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	0	0
State [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 0	$ 0