Income Taxes - Reconciliation of Effective Tax Rate (Details)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Federal statutory tax rate	35.00%	35.00%
State income taxes, net of federal benefit	2.30%	2.60%
Change in valuation allowance	0.00%	(0.10%)
Domestic production activities deduction	(2.70%)	(2.40%)
Other	0.10%	0.20%
Effective income tax rate	34.70%	35.30%