Loans and Leases and Allowance for Credit Losses - Risk category of loans by class of loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Risk category of loans by class of loans
PCI Loans		$ 58,646
Total loans	$ 10,132,510	8,812,553
Pass
Risk category of loans by class of loans
Total loans	9,857,796	8,558,459
Watch
Risk category of loans by class of loans
Total loans	114,766	93,703
Substandard
Risk category of loans by class of loans
Total loans	159,948	160,391
Doubtful / Loss
Risk category of loans by class of loans
Total loans		0
Commercial | Owner occupied commercial real estate
Risk category of loans by class of loans
Total loans	1,759,617
Commercial | Owner occupied commercial real estate | Pass
Risk category of loans by class of loans
Total loans	1,676,238
Commercial | Owner occupied commercial real estate | Watch
Risk category of loans by class of loans
Total loans	32,747
Commercial | Owner occupied commercial real estate | Substandard
Risk category of loans by class of loans
Total loans	50,632
Commercial | Income producing commercial real estate
Risk category of loans by class of loans
Total loans	2,177,857
Commercial | Income producing commercial real estate | Pass
Risk category of loans by class of loans
Total loans	2,089,510
Commercial | Income producing commercial real estate | Watch
Risk category of loans by class of loans
Total loans	59,548
Commercial | Income producing commercial real estate | Substandard
Risk category of loans by class of loans
Total loans	28,799
Commercial | Commercial & industrial
Risk category of loans by class of loans
Total loans	2,314,169
Commercial | Commercial & industrial | Pass
Risk category of loans by class of loans
Total loans	2,250,021
Commercial | Commercial & industrial | Watch
Risk category of loans by class of loans
Total loans	19,539
Commercial | Commercial & industrial | Substandard
Risk category of loans by class of loans
Total loans	44,609
Commercial | Construction
Risk category of loans by class of loans
Total loans	945,748
Commercial | Construction | Pass
Risk category of loans by class of loans
Total loans	933,498
Commercial | Construction | Watch
Risk category of loans by class of loans
Total loans	2,932
Commercial | Construction | Substandard
Risk category of loans by class of loans
Total loans	9,318
Commercial | Equipment financing
Risk category of loans by class of loans
Total loans	778,749
Commercial | Equipment financing | Pass
Risk category of loans by class of loans
Total loans	774,990
Commercial | Equipment financing | Substandard
Risk category of loans by class of loans
Total loans	3,759
Residential | Construction
Risk category of loans by class of loans
Total loans	230,231
Residential | Construction | Pass
Risk category of loans by class of loans
Total loans	229,512
Residential | Construction | Substandard
Risk category of loans by class of loans
Total loans	719
Residential | Residential mortgage
Risk category of loans by class of loans
Total loans	1,151,661
Residential | Residential mortgage | Pass
Risk category of loans by class of loans
Total loans	1,134,553
Residential | Residential mortgage | Substandard
Risk category of loans by class of loans
Total loans	17,108
Residential | Home equity lines of credit
Risk category of loans by class of loans
Total loans	653,798
Residential | Home equity lines of credit | Pass
Risk category of loans by class of loans
Total loans	649,420
Residential | Home equity lines of credit | Substandard
Risk category of loans by class of loans
Total loans	4,378
Consumer
Risk category of loans by class of loans
Total loans	120,680
Consumer | Pass
Risk category of loans by class of loans
Total loans	120,054
Consumer | Substandard
Risk category of loans by class of loans
Total loans	626
Loans receivable
Risk category of loans by class of loans
Total loans, excluding PCI loans		8,753,907
PCI Loans		58,646
Total loans	10,132,510	8,812,553
Loans receivable | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		8,517,776
PCI Loans		40,683
Loans receivable | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		83,930
PCI Loans		9,773
Loans receivable | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		152,201
PCI Loans		8,190
Loans receivable | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial
Risk category of loans by class of loans
Total loans, excluding PCI loans		6,622,646
PCI Loans		46,947
Total loans	7,976,140	6,669,593
Loans receivable | Commercial | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		6,406,957
PCI Loans		30,570
Loans receivable | Commercial | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		83,922
PCI Loans		9,773
Loans receivable | Commercial | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		131,767
PCI Loans		6,604
Loans receivable | Commercial | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial | Owner occupied commercial real estate
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,711,681
PCI Loans		8,546
Total loans	1,759,617	1,720,227
Loans receivable | Commercial | Owner occupied commercial real estate | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,638,398
PCI Loans		3,238
Loans receivable | Commercial | Owner occupied commercial real estate | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		24,563
PCI Loans		2,797
Loans receivable | Commercial | Owner occupied commercial real estate | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		48,720
PCI Loans		2,511
Loans receivable | Commercial | Owner occupied commercial real estate | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial | Income producing commercial real estate
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,980,722
PCI Loans		27,228
Total loans	2,177,857	2,007,950
Loans receivable | Commercial | Income producing commercial real estate | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,914,524
PCI Loans		19,648
Loans receivable | Commercial | Income producing commercial real estate | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		40,676
PCI Loans		6,305
Loans receivable | Commercial | Income producing commercial real estate | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		25,522
PCI Loans		1,275
Loans receivable | Commercial | Income producing commercial real estate | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial | Commercial & industrial
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,220,331
PCI Loans		326
Total loans	2,314,169	1,220,657
Loans receivable | Commercial | Commercial & industrial | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,156,366
PCI Loans		104
Loans receivable | Commercial | Commercial & industrial | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		16,385
PCI Loans		81
Loans receivable | Commercial | Commercial & industrial | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		47,580
PCI Loans		141
Loans receivable | Commercial | Commercial & industrial | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial | Construction
Risk category of loans by class of loans
Total loans, excluding PCI loans		969,353
PCI Loans		6,862
Total loans	945,748	976,215
Loans receivable | Commercial | Construction | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		960,251
PCI Loans		3,628
Loans receivable | Commercial | Construction | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		2,298
PCI Loans		590
Loans receivable | Commercial | Construction | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		6,804
PCI Loans		2,644
Loans receivable | Commercial | Construction | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial | Equipment financing
Risk category of loans by class of loans
Total loans, excluding PCI loans		740,559
PCI Loans		3,985
Total loans	778,749	744,544
Loans receivable | Commercial | Equipment financing | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		737,418
PCI Loans		3,952
Loans receivable | Commercial | Equipment financing | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Commercial | Equipment financing | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		3,141
PCI Loans		33
Loans receivable | Commercial | Equipment financing | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Residential | Construction
Risk category of loans by class of loans
Total loans, excluding PCI loans		236,063
PCI Loans		374
Total loans	230,231	236,437
Loans receivable | Residential | Construction | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		234,791
PCI Loans		348
Loans receivable | Residential | Construction | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Residential | Construction | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,272
PCI Loans		26
Loans receivable | Residential | Construction | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Residential | Residential mortgage
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,108,037
PCI Loans		9,579
Total loans	1,151,661	1,117,616
Loans receivable | Residential | Residential mortgage | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		1,093,902
PCI Loans		8,112
Loans receivable | Residential | Residential mortgage | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Residential | Residential mortgage | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		14,135
PCI Loans		1,467
Loans receivable | Residential | Residential mortgage | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Residential | Home equity lines of credit
Risk category of loans by class of loans
Total loans, excluding PCI loans		659,265
PCI Loans		1,410
Total loans	653,798	660,675
Loans receivable | Residential | Home equity lines of credit | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		654,619
PCI Loans		1,350
Loans receivable | Residential | Home equity lines of credit | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Residential | Home equity lines of credit | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		4,646
PCI Loans		60
Loans receivable | Residential | Home equity lines of credit | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		0
Loans receivable | Consumer
Risk category of loans by class of loans
Total loans, excluding PCI loans		127,896
PCI Loans		336
Total loans	$ 120,680	128,232
Loans receivable | Consumer | Pass
Risk category of loans by class of loans
Total loans, excluding PCI loans		127,507
PCI Loans		303
Loans receivable | Consumer | Watch
Risk category of loans by class of loans
Total loans, excluding PCI loans		8
PCI Loans		0
Loans receivable | Consumer | Substandard
Risk category of loans by class of loans
Total loans, excluding PCI loans		381
PCI Loans		33
Loans receivable | Consumer | Doubtful / Loss
Risk category of loans by class of loans
Total loans, excluding PCI loans		0
PCI Loans		$ 0