Loan and Lease Financings (Details 3) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	$ 4,358,288	$ 4,158,757
90 Days or More Past Due and Accruing	178	416
Total Accruing Loans	4,365,391	4,168,164
Nonaccrual	15,923	19,907
Total loans and leases	4,381,314	4,188,071
30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	4,657	5,169
60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	2,268	3,822
Commercial and agricultural
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	869,663	808,283
Total Accruing Loans	870,085	808,283
Nonaccrual	6,319	3,981
Total loans and leases	876,404	812,264
Commercial and agricultural | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	422	0
Commercial and agricultural | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	0	0
Auto and light truck
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	511,506	411,300
Total Accruing Loans	511,612	411,598
Nonaccrual	409	166
Total loans and leases	512,021	411,764
Auto and light truck | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	106	298
Auto and light truck | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	0	0
Medium and heavy duty truck
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	289,719	294,790
Total Accruing Loans	290,687	294,790
Nonaccrual	0	0
Total loans and leases	290,687	294,790
Medium and heavy duty truck | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	670	0
Medium and heavy duty truck | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	298	0
Aircraft
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	782,213	791,559
Total Accruing Loans	785,532	796,304
Nonaccrual	1,984	6,110
Total loans and leases	787,516	802,414
Aircraft | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	2,014	1,429
Aircraft | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	1,305	3,316
Construction equipment
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	537,610	493,131
Total Accruing Loans	537,891	494,677
Nonaccrual	1,206	1,248
Total loans and leases	539,097	495,925
Construction equipment | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	281	1,546
Construction equipment | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	0	0
Commercial real estate
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	717,312	713,482
Total Accruing Loans	717,349	713,615
Nonaccrual	2,729	5,555
Total loans and leases	720,078	719,170
Commercial real estate | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	37	133
Commercial real estate | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	0	0
Residential real estate and home equity
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	522,035	517,212
90 Days or More Past Due and Accruing	155	394
Total Accruing Loans	523,535	519,290
Nonaccrual	3,057	2,641
Total loans and leases	526,592	521,931
Residential real estate and home equity | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	762	1,310
Residential real estate and home equity | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	583	374
Consumer
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Current	128,230	129,000
90 Days or More Past Due and Accruing	23	22
Total Accruing Loans	128,700	129,607
Nonaccrual	219	206
Total loans and leases	128,919	129,813
Consumer | 30 to 59 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	365	453
Consumer | 60 to 89 Days Past Due
Recorded investment of loans and leases, segregated by class, with delinquency aging and nonaccrual status
Past Due	$ 82	$ 132