Income Taxes (Reconciliation of Statutory Federal Tax Rate) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal income tax at statutory rate	35.00%	34.90%	35.00%	34.90%
State and local taxes, net of federal benefit	5.20%	5.20%	5.20%	5.20%
Jobs tax credits, net	(8.10%)	(10.80%)	(7.40%)	(11.80%)
Nondeductible permanent items	0.50%	1.00%	0.50%	2.10%
Other	(2.40%)	0.00%	(1.20%)	0.00%
Effective income tax rate	30.20%	30.30%	32.10%	30.40%