Loan and Lease Financings (Details)	9 Months Ended
Sep. 30, 2016 USD ($) item	Dec. 31, 2015 USD ($)
Receivables [Abstract]
Number of methods to assess credit risk \| item	2
Loan and Lease Financings
Recorded investment in loans and leases	$ 4,179,417,000	$ 3,994,692,000
Loan and lease financings excluding residential real estate and consumer loans
Loan and Lease Financings
Recorded investment in loans and leases	3,538,489,000	3,382,084,000
Commercial and agricultural
Loan and Lease Financings
Recorded investment in loans and leases	786,167,000	744,749,000
Auto and light truck
Loan and Lease Financings
Recorded investment in loans and leases	400,809,000	425,236,000
Medium and heavy duty truck
Loan and Lease Financings
Recorded investment in loans and leases	271,478,000	278,254,000
Aircraft
Loan and Lease Financings
Recorded investment in loans and leases	836,977,000	778,012,000
Construction equipment
Loan and Lease Financings
Recorded investment in loans and leases	498,086,000	455,565,000
Commercial real estate
Loan and Lease Financings
Recorded investment in loans and leases	744,972,000	700,268,000
Credit Quality Grades 1-6 \| Loan and lease financings excluding residential real estate and consumer loans
Loan and Lease Financings
Recorded investment in loans and leases	3,461,489,000	3,278,484,000
Credit Quality Grades 1-6 \| Commercial and agricultural
Loan and Lease Financings
Recorded investment in loans and leases	758,615,000	710,030,000
Credit Quality Grades 1-6 \| Auto and light truck
Loan and Lease Financings
Recorded investment in loans and leases	396,001,000	413,836,000
Credit Quality Grades 1-6 \| Medium and heavy duty truck
Loan and Lease Financings
Recorded investment in loans and leases	270,255,000	275,367,000
Credit Quality Grades 1-6 \| Aircraft
Loan and Lease Financings
Recorded investment in loans and leases	809,233,000	750,264,000
Credit Quality Grades 1-6 \| Construction equipment
Loan and Lease Financings
Recorded investment in loans and leases	492,309,000	448,683,000
Credit Quality Grades 1-6 \| Commercial real estate
Loan and Lease Financings
Recorded investment in loans and leases	735,076,000	680,304,000
Credit Quality Grades 7-12
Loan and Lease Financings
Relationships reviewed quarterly as part of management's evaluation of the appropriateness of the reserve for loan and lease losses	100,000
Credit Quality Grades 7-12 \| Loan and lease financings excluding residential real estate and consumer loans
Loan and Lease Financings
Recorded investment in loans and leases	77,000,000	103,600,000
Credit Quality Grades 7-12 \| Commercial and agricultural
Loan and Lease Financings
Recorded investment in loans and leases	27,552,000	34,719,000
Credit Quality Grades 7-12 \| Auto and light truck
Loan and Lease Financings
Recorded investment in loans and leases	4,808,000	11,400,000
Credit Quality Grades 7-12 \| Medium and heavy duty truck
Loan and Lease Financings
Recorded investment in loans and leases	1,223,000	2,887,000
Credit Quality Grades 7-12 \| Aircraft
Loan and Lease Financings
Recorded investment in loans and leases	27,744,000	27,748,000
Credit Quality Grades 7-12 \| Construction equipment
Loan and Lease Financings
Recorded investment in loans and leases	5,777,000	6,882,000
Credit Quality Grades 7-12 \| Commercial real estate
Loan and Lease Financings
Recorded investment in loans and leases	$ 9,896,000	$ 19,964,000

Represents the amount of loans and leases where the internal credit quality grade is at or below a predetermined classification which are included in comprehensive analysis.

No definition available.

+ Details

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- Definition

Represents the number of methods to assess credit risk of loans and leases receivables.

+ References

No definition available.

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+ References

No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5074-111524

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