Income Taxes - Reconciliation Of Actual To Expected Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Computed “expected” income tax expense									$ 8,552	$ 8,646	$ 6,192
State income taxes, net									794	886	660
Non-deductible merger expenses									0	130	0
Tax-exempt interest on investment securities									(507)	(415)	(461)
Tax-exempt gain on purchase of mortgage affiliate									0	(1,050)	0
Amortization of investment in low income housing tax credit partnerships									2,684	1,337	969
Low income housing credits									(2,446)	(1,298)	(955)
Other									(293)	(63)	(159)
Total	$ 1,673	$ 2,678	$ 2,686	$ 1,747	$ 2,325	$ 1,982	$ 2,569	$ 1,297	$ 8,784	$ 8,173	$ 6,246