Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Allowance for Loan and Lease Losses and Corresponding Loan and Lease Balances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Allowance for loan and lease losses
Beginning balance	$ 31,936	$ 25,201
Provisions	14,455	3,999
Charge-offs	(4,972)	(2,348)
Recoveries	421	254
Ending balance	41,840	27,106
Ending balance:
Individually evaluated for impairment			$ 13,435		$ 7,559
Collectively evaluated for impairment			24,103		16,701
Allowance for loan and lease losses	31,936	27,106	41,840	$ 31,936	27,106
Loans and leases ending balance:
Individually evaluated for impairment			81,437		43,798
Collectively evaluated for impairment			3,535,394		3,260,357
Total loans and leases			3,860,259	3,785,661	3,567,566
Loans Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality			4,302		2,846
Loans and leases ending balance:
Loans acquired with deteriorated credit quality			243,428		263,411
Commercial Real Estate
Allowance for loan and lease losses
Beginning balance	7,965	7,540
Provisions	4,422	442
Charge-offs	(552)	(1,351)
Recoveries	16	29
Ending balance	11,851	6,660
Ending balance:
Individually evaluated for impairment			3,634		1,403
Collectively evaluated for impairment			6,115		4,141
Allowance for loan and lease losses	11,851	6,660	11,851	7,965	6,660
Loans and leases ending balance:
Individually evaluated for impairment			32,974		17,354
Collectively evaluated for impairment			1,134,090		1,103,730
Total loans and leases			1,294,959	1,276,542	1,262,283
Commercial Real Estate | Loans Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality			2,102		1,116
Loans and leases ending balance:
Loans acquired with deteriorated credit quality			127,895		141,199
Residential Real Estate
Allowance for loan and lease losses
Beginning balance	1,990	1,751
Provisions	784	218
Charge-offs	(5)
Recoveries	9	1
Ending balance	2,778	1,970
Ending balance:
Individually evaluated for impairment			92		34
Collectively evaluated for impairment			1,685		1,516
Allowance for loan and lease losses	2,778	1,970	2,778	1,990	1,970
Loans and leases ending balance:
Individually evaluated for impairment			1,960		2,060
Collectively evaluated for impairment			597,839		590,212
Total loans and leases			693,997	711,822	699,036
Residential Real Estate | Loans Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality			1,001		420
Loans and leases ending balance:
Loans acquired with deteriorated credit quality			94,198		106,764
Construction, Land Development, and Other Land
Allowance for loan and lease losses
Beginning balance	610	466
Provisions	394	70
Ending balance	1,004	536
Ending balance:
Collectively evaluated for impairment			915		536
Allowance for loan and lease losses	1,004	536	1,004	610	536
Loans and leases ending balance:
Individually evaluated for impairment			2,577
Collectively evaluated for impairment			269,908		210,548
Total loans and leases			277,776	278,657	213,659
Construction, Land Development, and Other Land | Loans Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality			89
Loans and leases ending balance:
Loans acquired with deteriorated credit quality			5,291		3,111
Commercial and Industrial
Allowance for loan and lease losses
Beginning balance	19,377	12,932
Provisions	8,546	3,032
Charge-offs	(3,958)	(352)
Recoveries	174	18
Ending balance	24,139	15,630
Ending balance:
Individually evaluated for impairment			9,709		6,122
Collectively evaluated for impairment			13,320		8,200
Allowance for loan and lease losses	24,139	15,630	24,139	19,377	15,630
Loans and leases ending balance:
Individually evaluated for impairment			43,926		24,384
Collectively evaluated for impairment			1,354,825		1,153,471
Total loans and leases			1,414,559	1,331,565	1,189,818
Commercial and Industrial | Loans Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality			1,110		1,308
Loans and leases ending balance:
Loans acquired with deteriorated credit quality			15,808		11,963
Installment and Other
Allowance for loan and lease losses
Beginning balance	50	49
Provisions	3	14
Ending balance	53	63
Ending balance:
Collectively evaluated for impairment			53		61
Allowance for loan and lease losses	53	63	53	50	63
Loans and leases ending balance:
Collectively evaluated for impairment			5,485		12,428
Total loans and leases			5,721	6,565	12,802
Installment and Other | Loans Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality					2
Loans and leases ending balance:
Loans acquired with deteriorated credit quality			236		374
Lease Financing Receivables
Allowance for loan and lease losses
Beginning balance	1,944	2,463
Provisions	306	223
Charge-offs	(457)	(645)
Recoveries	222	206
Ending balance	2,015	2,247
Ending balance:
Collectively evaluated for impairment			2,015		2,247
Allowance for loan and lease losses	$ 2,015	$ 2,247	2,015	1,944	2,247
Loans and leases ending balance:
Collectively evaluated for impairment			173,247		189,968
Total loans and leases			$ 173,247	$ 180,510	$ 189,968