Subsequent Events (Details) $ in Thousands	Jan. 03, 2017 USD ($) item shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Subsequent events
Assets		$ 8,900,592	$ 8,557,348
Deposits.		7,334,423	7,100,428
Loans		6,643,326	$ 5,970,044
SBFC
Subsequent events
Business consideration received, common stock (in shares) | shares	4,978,338
Fixed exchange ratio for shares issued (as a percent)	0.7307
Purchase consideration	$ 435,100
Assets		1,800,000
Deposits.		1,500,000
Loans		$ 1,100,000
Number of offices | item	12
Subsequent event | SBFC
Subsequent events
Business consideration received, common stock (in shares) | shares	4,978,338
Fixed exchange ratio for shares issued (as a percent)	0.7307
Purchase consideration	$ 435,100
Number of offices | item	12