Income Taxes - Reconciliation of The Provision for Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax expense computed at statutory rate	$ 31,418,000	$ 11,098,000	$ 23,271,000
State income taxes, net of federal tax benefit	4,015,000	998,000	2,916,000
Federal jobs credits	(3,900,000)	(2,925,000)	(7,121,000)
Tax exempt interest	(132,000)	(13,000)	(29,000)
Other, net	339,000	700,000	323,000
Tax Provision	31,740,000	$ 9,858,000	$ 19,360,000
Unrecognized Tax Benefits	$ 0