Loans and Allowance for Loan Losses - Activity in the Allowance for Loan Losses, by Portfolio Segment, for the Current Year (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 56,694	$ 42,086
Provision for loan losses	43,240	38,148	$ 26,393
Balance, end of period	68,244	56,694	42,086
Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	56,599	41,668	36,286
Provision for loan losses	40,776	34,849	24,527
Charge-offs	(33,821)	(23,216)	(23,498)
Recoveries	4,246	3,298	4,353
Net charge-offs	(29,575)	(19,918)	(19,145)
Balance, end of period	67,800	56,599	41,668
Loans individually evaluated for impairment	5,747	684
Loans collectively evaluated for impairment	62,053	55,915
Loans acquired
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	95	418
Provision for loan losses	2,464	3,299	1,866
Charge-offs	(3,015)	(3,622)	(2,402)
Recoveries	900
Balance, end of period	444	95	418
Other Consumer and Other | Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	2,419	3,596	2,951
Provision for loan losses	2,287	4,903	2,173
Charge-offs	(4,894)	(6,637)	(3,767)
Recoveries	2,357	557	2,239
Net charge-offs	(2,537)	(6,080)	(1,528)
Balance, end of period	2,169	2,419	3,596
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	2,169	2,419
Commercial | Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	20,514	7,007	7,739
Provision for loan losses	24,000	19,385	7,002
Charge-offs	(22,023)	(6,623)	(7,837)
Recoveries	372	745	103
Net charge-offs	(21,651)	(5,878)	(7,734)
Balance, end of period	22,863	20,514	7,007
Loans individually evaluated for impairment	5,007	437
Loans collectively evaluated for impairment	17,856	20,077
Real Estate | Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	29,743	27,281	21,817
Provision for loan losses	10,797	7,376	12,463
Charge-offs	(2,319)	(5,905)	(7,989)
Recoveries	496	991	990
Net charge-offs	(1,823)	(4,914)	(6,999)
Balance, end of period	38,717	29,743	27,281
Loans individually evaluated for impairment	740	247
Loans collectively evaluated for impairment	37,977	29,496
Consumer | Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Net charge-offs	(6,101)	(9,126)
Consumer | Credit Card | Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	3,923	3,784	3,779
Provision for loan losses	3,692	3,185	2,889
Charge-offs	(4,585)	(4,051)	(3,905)
Recoveries	1,021	1,005	1,021
Net charge-offs	(3,564)	(3,046)	(2,884)
Balance, end of period	4,051	3,923	$ 3,784
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	$ 4,051	$ 3,923