Loans and the Allowance for Loan Losses (Details) - Aging analysis - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Nonaccrual		$ 61,696	$ 49,481
Total Past Due		98,000	58,797
Current		6,149,681	5,059,497
Loans		6,247,681	5,118,294
30 - 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		18,544	5,576
60 - 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		4,939	633
90 Days or Greater Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		12,821	3,107
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual		33,019	31,455
Total Past Due		38,204	34,801
Current		1,483,763	1,094,860
Loans	[1]	1,521,967	1,129,661
Commercial Portfolio Segment [Member] | 30 - 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		1,445	239
Commercial Portfolio Segment [Member] | 60 - 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		558
Commercial Portfolio Segment [Member] | 90 Days or Greater Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		3,182	3,107
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual		10,111	8,338
Total Past Due		33,064	10,808
Current		3,750,486	3,031,151
Loans		3,783,550	3,041,959
Commercial Real Estate Portfolio Segment [Member] | 30 - 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		13,258	1,980
Commercial Real Estate Portfolio Segment [Member] | 60 - 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		4,140	490
Commercial Real Estate Portfolio Segment [Member] | 90 Days or Greater Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		5,555
Commercial construction [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual		14,015	6,773
Total Past Due		16,487	6,773
Current		601,260	616,553
Loans		617,747	623,326
Commercial construction [Member] | 30 - 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		2,472
Commercial construction [Member] | 60 - 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due
Commercial construction [Member] | 90 Days or Greater Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual		4,551	2,915
Total Past Due		10,243	6,415
Current		312,321	313,605
Loans		322,564	320,020
Residential Portfolio Segment [Member] | 30 - 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		1,367	3,357
Residential Portfolio Segment [Member] | 60 - 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		241	143
Residential Portfolio Segment [Member] | 90 Days or Greater Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		4,084
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual
Total Past Due		2
Current		1,851	3,328
Loans		1,853	3,328
Consumer Portfolio Segment [Member] | 30 - 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due		2
Consumer Portfolio Segment [Member] | 60 - 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due
Consumer Portfolio Segment [Member] | 90 Days or Greater Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due

[1] Included in commercial loans as of December 31, 2020 were PPP loans of $397.5 million.