Finance Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		$ 113,392	[1]	$ 67,740
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	(1,137)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	1,157
Financing Receivable, Allowance for Credit Loss, Writeoff		(8,446)
Financing Receivable, Allowance for Credit Loss, Recovery		1,578
Financing Receivable, Credit Loss, Expense (Reversal)		52,500
Financing Receivable, Nonaccrual, No Allowance	[4]	35,528
Finance Receivable, Nonaccrual, with allowance	[4]	31,332
Financing Receivable, Nonaccrual	[4]	66,860		45,892
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		21,086	[1]	17,594
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	(1,984)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	49
Financing Receivable, Allowance for Credit Loss, Writeoff		(2,309)
Financing Receivable, Allowance for Credit Loss, Recovery		289
Financing Receivable, Credit Loss, Expense (Reversal)		7,447
Financing Receivable, Nonaccrual, No Allowance		30,925
Finance Receivable, Nonaccrual, with allowance		3,804
Financing Receivable, Nonaccrual		34,729		22,574
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		45,009	[1]	32,935
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	(13,048)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	337
Financing Receivable, Allowance for Credit Loss, Writeoff		(3,885)
Financing Receivable, Allowance for Credit Loss, Recovery		9
Financing Receivable, Credit Loss, Expense (Reversal)		28,661
Financing Receivable, Nonaccrual, No Allowance		0
Finance Receivable, Nonaccrual, with allowance		10,195
Financing Receivable, Nonaccrual		10,195		3,016
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		5,397	[1]	6,053
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	(3,652)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	0
Financing Receivable, Allowance for Credit Loss, Writeoff		0
Financing Receivable, Allowance for Credit Loss, Recovery		0
Financing Receivable, Credit Loss, Expense (Reversal)		2,996
Small Business [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		5,095	[1]	1,746
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	495
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	0
Financing Receivable, Allowance for Credit Loss, Writeoff		(380)
Financing Receivable, Allowance for Credit Loss, Recovery		33
Financing Receivable, Credit Loss, Expense (Reversal)		3,201
Financing Receivable, Nonaccrual, No Allowance		10
Finance Receivable, Nonaccrual, with allowance		815
Financing Receivable, Nonaccrual		825		311
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		14,275	[1]	3,440
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	9,828
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	423
Financing Receivable, Allowance for Credit Loss, Writeoff		(105)
Financing Receivable, Allowance for Credit Loss, Recovery		2
Financing Receivable, Credit Loss, Expense (Reversal)		687
Financing Receivable, Nonaccrual, No Allowance		4,593
Finance Receivable, Nonaccrual, with allowance		10,935
Financing Receivable, Nonaccrual		15,528		13,360
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		22,060	[1]	5,576
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	7,012
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	319
Financing Receivable, Allowance for Credit Loss, Writeoff		(142)
Financing Receivable, Allowance for Credit Loss, Recovery		210
Financing Receivable, Credit Loss, Expense (Reversal)		9,085
Financing Receivable, Nonaccrual, No Allowance		0
Finance Receivable, Nonaccrual, with allowance		5,427
Financing Receivable, Nonaccrual		5,427		6,570
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss		470	[1]	396
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method	[2]	212
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	[3]	29
Financing Receivable, Allowance for Credit Loss, Writeoff		(1,625)
Financing Receivable, Allowance for Credit Loss, Recovery		1,035
Financing Receivable, Credit Loss, Expense (Reversal)		423
Financing Receivable, Nonaccrual, No Allowance		0
Finance Receivable, Nonaccrual, with allowance		156
Financing Receivable, Nonaccrual		$ 156		$ 61

[1] Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $36.0 million at December 31, 2020

[2] Represents adjustment needed to reflect the cumulative day one impact pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.1 million decrease to the allowance attributable to the change in accounting methodology for estimating the allowance for credit losses resulting from the Company's adoption of the standard.

[3] Represents adjustment needed to reflect the day one reclassification of the Company's PCI loan balances to PCD and the associated gross-up, pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.2 million increase to the allowance resulting from the day one reclassification.

[4] Included in these amounts are $22.2 million and $24.8 million of nonaccruing TDRs at December 31, 2020 and December 31, 2019, respectively.