Income Taxes (Schedule of Provisions of Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Income Tax Expense (Benefit), Continuing Operations
Federal	$ 61,073	$ 31,132	$ 32,142
State and local	10,560	7,670	6,142
Foreign	466	160	0
Total current provision	72,099	38,962	38,284
Deferred Income Tax Expense (Benefit), Continuing Operations
Federal	(2,506)	466	(4,545)
State and local	(110)	596	(948)
Foreign	18	0	0
Total deferred provision	(2,598)	1,062	(5,493)
Provision for income taxes	$ 69,501	$ 40,024	$ 32,791