Loans and Allowance for Credit Losses (ALLL Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses, beginning of period	$ 250,579	$ 114,703	$ 108,671	$ 109,931
Provision for credit losses	25,414	(2,747)	150,842	7,534
Charge-offs	(19,178)	(1,711)	(26,984)	(7,844)
Recoveries	3,138	1,896	3,682	2,520
Allowance for loan and lease losses, end of period	266,123	112,141	266,123	112,141
Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses, beginning of period	12,576	10,952	11,154	10,788
Charge-offs	0	0	(31)	0
Recoveries	43	153	46	167
Allowance for loan and lease losses, end of period	10,695	11,236	10,695	11,236
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses, beginning of period	238,003	103,751	97,517	99,143
Charge-offs	(19,178)	1,711	(26,953)	7,844
Recoveries	3,095	1,743	3,636	2,353
Allowance for loan and lease losses, end of period	255,428	100,905	255,428	100,905
Adjustments for New Accounting Principle, Early Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses, end of period	27,305		27,305
Adjustments for New Accounting Principle, Early Adoption [Member] \| Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses, end of period	8,098		8,098
Adjustments for New Accounting Principle, Early Adoption [Member] \| Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan and lease losses, end of period	19,207		19,207
Funded Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Provision for credit losses	31,584	(2,747)	153,449	7,534
Funded Loans [Member] \| Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Provision for credit losses	(1,924)	131	(8,572)	281
Funded Loans [Member] \| Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Provision for credit losses	$ 33,508	$ (2,878)	$ 162,021	$ 7,253

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

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- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

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