Loans and Allowance for Loan Losses - Table of loan payment estimates - (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jan. 03, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
SBFC
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Contractual principal and interest		$ 73,365
Non-accretable difference		(12,912)
Cash flows expected to be collected		60,453
Accretable difference		(4,603)
Carrying value		55,850
Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Contractual principal and interest	$ 812,892		$ 778,822	$ 912,010
Non-accretable difference	(31,273)		(17,502)	(26,833)
Cash flows expected to be collected	781,619		761,320	885,177
Accretable Yield	(149,723)		(155,379)	(188,863)
Carrying value	631,896		605,941	696,314
Allowance for loan losses on acquired loans	(4,556)		(3,395)	(3,877)	$ (3,706)
Acquired credit impaired loans | SBFC
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Contractual principal and interest		73,365
Non-accretable difference		(12,912)
Cash flows expected to be collected		60,453
Accretable difference		(4,603)
Carrying value		$ 55,850
Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	1,715,642		836,699	999,238
Residential real estate | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	266,484		258,100	298,537
Allowance for loan losses on acquired loans	(3,108)		(2,419)	(2,863)	(2,986)
Commercial non-owner occupied real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	359,747		44,718	49,554
Commercial owner occupied real estate loan | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	238,612		27,195	37,356
Consumer real estate | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	58,688		59,300	67,612
Allowance for loan losses on acquired loans	(589)		(558)	(606)	(313)
Consumer real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	736,989		569,149	678,860
Commercial and industrial | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	26,225		25,347	28,948
Allowance for loan losses on acquired loans	(395)		(238)	(208)	(174)
Commercial and industrial | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	136,309		13,641	21,109
Other income producing property | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	92,044		39,342	49,123
Consumer | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	58,688		59,300	67,612
Consumer | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	151,941		142,654	163,236
Commercial | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	826,712		124,896	157,142
Commercial loans 1000000 or more | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	8,594		8,617	12,445
Construction and land development | Commercial non-owner occupied real estate | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	57,343		44,373	51,379
Allowance for loan losses on acquired loans	(130)		(139)	(154)	(177)
Construction and land development | Commercial non-owner occupied real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	141,897		10,090	13,024
Other commercial non-owner occupied real estate | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value			210,204
Other commercial non-owner occupied real estate | Commercial non-owner occupied real estate | Acquired credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	214,562		210,204	237,393
Allowance for loan losses on acquired loans	(334)		(41)	(46)	$ (56)
Other commercial non-owner occupied real estate | Commercial non-owner occupied real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	217,850		34,628	36,530
Home equity loans | Consumer real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	186,411		160,879	184,388
Consumer | Consumer real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	151,941		142,654	163,236
Other Consumer | Consumer real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	888,930		711,803	842,096
Consumer Owner Occupied Loans | Consumer real estate | Acquired non-credit impaired loans
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Carrying value	$ 550,578		$ 408,270	$ 494,472