Subsequent Event (Details) - USD ($) $ in Thousands	Apr. 28, 2017	Mar. 10, 2017
Subsequent Event [Line Items]
Acquisition, assets assumed		$ 1,233,643
Whitney Bank [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Acquisition, cash	$ 655,000
Transaction premium	35,000
Whitney Bank [Member] | Subsequent Event [Member] | Deposits [Member]
Subsequent Event [Line Items]
Acquisition, assets assumed	1,600,000
Whitney Bank [Member] | Subsequent Event [Member] | Cash, Securities, Consumer And Residential Mortgage Loans [Member]
Subsequent Event [Line Items]
Acquisition, assets assumed	$ 1,000,000