Loans and Leases Impaired Collateral (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 307,907	$ 256,410
Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	91,281	59,550
Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	216,626	196,860
Collateral Value
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	135,300	109,800
Commercial Portfolio Segment [Member] | Commercial non-mortgage
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	125,799	102,254
Commercial Portfolio Segment [Member] | Commercial non-mortgage | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	11,337	10,682
Commercial Portfolio Segment [Member] | Commercial non-mortgage | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	114,462	91,572
Commercial Portfolio Segment [Member] | Asset-based
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	3,760	139
Commercial Portfolio Segment [Member] | Asset-based | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Commercial Portfolio Segment [Member] | Asset-based | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	3,760	139
Commercial Portfolio Segment [Member] | Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	21,583	23,297
Commercial Portfolio Segment [Member] | Commercial real estate | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	15,708	14,097
Commercial Portfolio Segment [Member] | Commercial real estate | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	5,875	9,200
Commercial Portfolio Segment [Member] | Equipment financing
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	7,182	5,433
Commercial Portfolio Segment [Member] | Equipment financing | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Commercial Portfolio Segment [Member] | Equipment financing | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	7,182	5,433
Commercial Portfolio Segment [Member] | Residential
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment		90,096
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment		256,410
Consumer Portfolio Segment [Member] | Residential
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	100,443	90,096
Consumer Portfolio Segment [Member] | Residential | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	35,379	17,635
Consumer Portfolio Segment [Member] | Residential | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	65,064	72,461
Consumer Portfolio Segment [Member] | Home equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	48,461	35,191
Consumer Portfolio Segment [Member] | Home equity | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	28,857	17,136
Consumer Portfolio Segment [Member] | Home equity | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	19,604	18,055
Consumer Portfolio Segment [Member] | Consumer Loan
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	679	0
Consumer Portfolio Segment [Member] | Consumer Loan | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Consumer Portfolio Segment [Member] | Consumer Loan | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 679	$ 0