Other Real Estate and Covered Other Real Estate - Other Real Estate, Excluding Covered Other Real Estate, By Type of Property (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Other real estate, excluding covered other real estate [Line Items]
Other real estate, excluding covered other real estate	$ 71,806	$ 77,177	$ 90,175	$ 92,509
Construction, Land Development And Other Land Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Other real estate, excluding covered other real estate	44,405	47,550
1 - 4 Family Residential Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Other real estate, excluding covered other real estate	8,576	10,732
Nonfarm, Nonresidential Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Other real estate, excluding covered other real estate	16,732	16,717
Other Real Estate Properties [Member]
Other real estate, excluding covered other real estate [Line Items]
Other real estate, excluding covered other real estate	$ 2,093	$ 2,178