Loans and Leases (Loans and Leases Outstanding) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
PCD loans	$ 432,773	$ 462,882
Total loans and leases	33,180,851	32,791,975
SBA-PPP
Loans and leases, not acquired in a transfer accounted for as debt securities	2,800,000
Commercial
Loans and leases, not acquired in a transfer accounted for as debt securities	23,097,302	22,558,060
Commercial \| Construction and land development
Loans and leases, not acquired in a transfer accounted for as debt securities	1,022,087	985,424
Commercial \| Owner occupied commercial mortgage
Loans and leases, not acquired in a transfer accounted for as debt securities	11,340,966	11,165,012
Commercial \| Non-owner occupied commercial mortgage
Loans and leases, not acquired in a transfer accounted for as debt securities	3,017,898	2,987,689
Commercial \| Commercial and industrial and leases
Loans and leases, not acquired in a transfer accounted for as debt securities	4,946,445	5,013,644
Commercial \| SBA-PPP
Loans and leases, not acquired in a transfer accounted for as debt securities	2,769,906	2,406,291
Consumer
Loans and leases, not acquired in a transfer accounted for as debt securities	9,650,776	9,771,033
Consumer \| Construction and land development
Loans and leases, not acquired in a transfer accounted for as debt securities	336,065	348,123
Consumer \| Consumer auto
Loans and leases, not acquired in a transfer accounted for as debt securities	1,271,586	1,255,402
Consumer \| Residential mortgage
Loans and leases, not acquired in a transfer accounted for as debt securities	5,566,026	5,561,686
Consumer \| Revolving mortgage
Loans and leases, not acquired in a transfer accounted for as debt securities	1,938,422	2,052,854
Consumer \| Consumer other
Loans and leases, not acquired in a transfer accounted for as debt securities	$ 538,677	$ 552,968

All loans and leases, excluding purchased-credit impaired loans accounted for under ASC 310-30.

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- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and other-than-temporary impairments), for loans accounted for as debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121585399&loc=d3e13503-111538

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

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