Loans and the Allowance for Loan Losses (Details) - Composition of loan portfolio - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Gross loans		$ 6,247,681	$ 5,118,294
Net deferred fees		(11,374)	(4,767)
Total loans receivable		6,236,307	5,113,527
Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Gross loans	[1]	1,521,967	1,129,661
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Gross loans		3,783,550	3,041,959
Commercial construction [Member]
Financing Receivable, Impaired [Line Items]
Gross loans		617,747	623,326
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Gross loans		322,564	320,020
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Gross loans		$ 1,853	$ 3,328

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