Credit Risk Profile Based on Payment Activity - Originated and Non-PCI Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	$ 9,430,761	$ 7,465,794	$ 6,520,512
Real estate - residential [Member] | Prime [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	492,227	319,827
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	446,347	411,266	381,248
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	41,857	39,090	$ 23,981
Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	125,361	115,709
Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	729,963	643,586
Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	291,570	310,296
Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	154,777	100,970
Originated and Non-PCI Loans [Member] | Real estate - residential [Member] | Prime [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	492,227	319,827
Originated and Non-PCI Loans [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	41,857	39,090
Originated and Non-PCI Loans [Member] | Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	125,361	115,709
Originated and Non-PCI Loans [Member] | Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	729,963	643,586
Originated and Non-PCI Loans [Member] | Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	291,570	310,296
Originated and Non-PCI Loans [Member] | Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	154,777	100,970
Originated and Non-PCI Loans [Member] | Performing [Member] | Real estate - residential [Member] | Prime [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	491,427	319,265
Originated and Non-PCI Loans [Member] | Performing [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	41,857	39,090
Originated and Non-PCI Loans [Member] | Performing [Member] | Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	125,348	115,672
Originated and Non-PCI Loans [Member] | Performing [Member] | Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	726,439	643,567
Originated and Non-PCI Loans [Member] | Performing [Member] | Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	291,102	309,736
Originated and Non-PCI Loans [Member] | Performing [Member] | Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	152,180	100,900
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Real estate - residential [Member] | Prime [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	800	562
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	13	37
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	3,524	19
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	468	560
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	$ 2,597	$ 70