Fair Value - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) Region	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Nonfinancial Assets and Liabilities [Abstract]
Outstanding balances in impaired loans	$ 41,100		$ 26,500
Key market regions | Region	5
Foreclosed assets measured at fair value	$ 3,300	$ 8,700
Allowance for possible loan losses, Charge-offs for foreclosed assets upon initial recognition	1,400	2,300
Foreclosed assets re-measured after initial recognition	12,200	13,700
Write-downs of allowance for foreclosed assets after initial recognition	$ 1,100	882
Estimated fair value of financial instruments with immediate and shorter-term maturities maximum	90 days
Noninterest gain (loss) Mortgage banking, net for changes in fair value of LHFS	$ 2,800	382
Interest earned on LHFS included in Interest and fees on LHFS and LHFI	867	$ 1,100
GNMA optional repurchase loans	$ 34,900		$ 36,000