Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 17,667	$ 48,440	$ 17,821	$ 17,667	$ 17,820
Initial PCD Allowance	2,800			2,786
Provision for credit losses on loans		7,057	896	15,657	1,260
Charge-offs		(575)	(714)	(1,288)	(1,375)
Recoveries		168	302	477	600
Balance, end of period	22,577	55,090	18,305	55,090	18,305
Impact of adopting ASC 326
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	19,791			19,791
Balance, end of period	17,667
Mortgage warehouse
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	1,077	1,055	1,014	1,077	1,006
Initial PCD Allowance				0
Provision for credit losses on loans		135	26	113	34
Charge-offs		0	0	0	0
Recoveries		0	0	0	0
Balance, end of period	0	1,190	1,040	1,190	1,040
Mortgage warehouse | Impact of adopting ASC 326
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	0			0
Balance, end of period	1,077
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	11,996	32,550	11,556	11,996	10,495
Initial PCD Allowance				2,786
Provision for credit losses on loans		6,603	590	13,519	1,712
Charge-offs		(15)	(339)	(84)	(416)
Recoveries		9	74	98	90
Balance, end of period		39,147	11,881	39,147	11,881
Commercial | Impact of adopting ASC 326
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	10,832			10,832
Real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	923	5,654	1,588	923	1,676
Initial PCD Allowance				0
Provision for credit losses on loans		202	185	902	70
Charge-offs		(34)	(48)	(60)	(48)
Recoveries		10	7	19	34
Balance, end of period		5,832	1,732	5,832	1,732
Real estate | Impact of adopting ASC 326
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	4,048			4,048
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	3,671	9,181	3,663	3,671	4,643
Initial PCD Allowance				0
Provision for credit losses on loans		117	95	1,123	(556)
Charge-offs		(526)	(327)	(1,144)	(911)
Recoveries		149	221	360	476
Balance, end of period		$ 8,921	$ 3,652	8,921	$ 3,652
Consumer | Impact of adopting ASC 326
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 4,911			$ 4,911