XML 48 R37.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Loan and Lease Financings (Details) | 9 Months Ended |
--- | --- | ---
Sep. 30, 2022 USD ($) item class | Dec. 31, 2021 USD ($)
Receivables [Abstract] |  |
Number of methods to assess credit risk | item | 2 |
Loan and Lease Financings |  |
Number of methods to assess credit risk | item | 2 |
PPP loan balance | $ 6,350,000 |
PPP loans receivable deferred income | $ 130,000 |
Number of domestic aircraft loan pools | class | 2 |
Amortized cost of loans and leases | $ 5,762,078,000 | $ 5,346,214,000
Commercial and agricultural |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 122,652,000 | 238,194,000
Financing receivable originated one year prior to current fiscal year | 129,812,000 | 124,141,000
Financing receivable originated two years prior to current fiscal year | 87,017,000 | 64,411,000
Financing receivable originated three years prior to current fiscal year | 41,734,000 | 57,604,000
Financing receivable originated four years prior to current fiscal year | 21,838,000 | 34,549,000
Financing receivable originated five years or more prior to current fiscal year | 20,207,000 | 20,668,000
Revolving Loans | 412,502,000 | 379,145,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | $ 835,762,000 | 918,712,000
Commercial and agricultural | Minimum |  |
Loan and Lease Financings |  |
Expected life of underlying collateral | 3 years |
Commercial and agricultural | Maximum |  |
Loan and Lease Financings |  |
Expected life of underlying collateral | 7 years |
Solar |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | $ 69,556,000 | 159,244,000
Financing receivable originated one year prior to current fiscal year | 115,921,000 | 43,211,000
Financing receivable originated two years prior to current fiscal year | 38,343,000 | 87,475,000
Financing receivable originated three years prior to current fiscal year | 78,442,000 | 19,703,000
Financing receivable originated four years prior to current fiscal year | 19,336,000 | 34,889,000
Financing receivable originated five years or more prior to current fiscal year | 37,037,000 | 3,780,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 358,635,000 | 348,302,000
Auto and light truck |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 401,341,000 | 341,933,000
Financing receivable originated one year prior to current fiscal year | 191,927,000 | 134,461,000
Financing receivable originated two years prior to current fiscal year | 81,807,000 | 80,047,000
Financing receivable originated three years prior to current fiscal year | 45,103,000 | 28,824,000
Financing receivable originated four years prior to current fiscal year | 15,446,000 | 16,690,000
Financing receivable originated five years or more prior to current fiscal year | 7,700,000 | 1,820,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | $ 743,324,000 | 603,775,000
Auto and light truck | Minimum |  |
Loan and Lease Financings |  |
Loan amortization period | 18 months |
Direct finance lease term | 3 years |
Auto and light truck | Maximum |  |
Loan and Lease Financings |  |
Loan amortization period | 4 years |
Direct finance lease term | 7 years |
Medium and heavy duty truck |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | $ 114,007,000 | 92,252,000
Financing receivable originated one year prior to current fiscal year | 72,478,000 | 68,354,000
Financing receivable originated two years prior to current fiscal year | 50,579,000 | 57,967,000
Financing receivable originated three years prior to current fiscal year | 38,281,000 | 23,210,000
Financing receivable originated four years prior to current fiscal year | 12,679,000 | 12,419,000
Financing receivable originated five years or more prior to current fiscal year | 5,044,000 | 5,538,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | $ 293,068,000 | 259,740,000
Medium and heavy duty truck | Minimum |  |
Loan and Lease Financings |  |
Period of amortization to reach equity position in collateral | 3 years |
Medium and heavy duty truck | Maximum |  |
Loan and Lease Financings |  |
Period of amortization to reach equity position in collateral | 4 years |
Aircraft |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | $ 317,766,000 | 386,036,000
Financing receivable originated one year prior to current fiscal year | 292,885,000 | 291,546,000
Financing receivable originated two years prior to current fiscal year | 239,816,000 | 85,916,000
Financing receivable originated three years prior to current fiscal year | 60,565,000 | 50,518,000
Financing receivable originated four years prior to current fiscal year | 33,028,000 | 47,479,000
Financing receivable originated five years or more prior to current fiscal year | 49,405,000 | 32,062,000
Revolving Loans | 4,530,000 | 4,844,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | $ 997,995,000 | 898,401,000
Aircraft | Minimum |  |
Loan and Lease Financings |  |
Loan amortization period | 10 years |
Aircraft | Maximum |  |
Loan and Lease Financings |  |
Loan amortization period | 15 years |
Construction equipment |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | $ 381,864,000 | 340,694,000
Financing receivable originated one year prior to current fiscal year | 244,019,000 | 209,741,000
Financing receivable originated two years prior to current fiscal year | 122,897,000 | 111,012,000
Financing receivable originated three years prior to current fiscal year | 70,561,000 | 48,490,000
Financing receivable originated four years prior to current fiscal year | 24,686,000 | 13,581,000
Financing receivable originated five years or more prior to current fiscal year | 7,784,000 | 5,031,000
Revolving Loans | 22,426,000 | 18,937,000
Revolving Loans Converted to Term | 4,455,000 | 6,787,000
Amortized cost of loans and leases | 878,692,000 | 754,273,000
Commercial real estate |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 208,865,000 | 230,919,000
Financing receivable originated one year prior to current fiscal year | 171,049,000 | 156,065,000
Financing receivable originated two years prior to current fiscal year | 136,376,000 | 153,533,000
Financing receivable originated three years prior to current fiscal year | 121,694,000 | 142,329,000
Financing receivable originated four years prior to current fiscal year | 108,587,000 | 132,850,000
Financing receivable originated five years or more prior to current fiscal year | 190,556,000 | 113,254,000
Revolving Loans | 296,000 | 391,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 937,423,000 | 929,341,000
Residential real estate and home equity |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 89,237,000 | 105,345,000
Financing receivable originated one year prior to current fiscal year | 101,376,000 | 114,682,000
Financing receivable originated two years prior to current fiscal year | 102,314,000 | 41,185,000
Financing receivable originated three years prior to current fiscal year | 35,269,000 | 9,719,000
Financing receivable originated four years prior to current fiscal year | 7,274,000 | 12,141,000
Financing receivable originated five years or more prior to current fiscal year | 86,402,000 | 90,301,000
Revolving Loans | 142,723,000 | 122,574,000
Revolving Loans Converted to Term | 4,007,000 | 4,643,000
Amortized cost of loans and leases | 568,602,000 | 500,590,000
Consumer |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 59,856,000 | 58,903,000
Financing receivable originated one year prior to current fiscal year | 39,253,000 | 24,414,000
Financing receivable originated two years prior to current fiscal year | 15,145,000 | 17,074,000
Financing receivable originated three years prior to current fiscal year | 9,085,000 | 8,314,000
Financing receivable originated four years prior to current fiscal year | 3,869,000 | 2,296,000
Financing receivable originated five years or more prior to current fiscal year | 1,046,000 | 701,000
Revolving Loans | 20,323,000 | 21,378,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 148,577,000 | 133,080,000
Credit Quality Grades 1-6 | Commercial and agricultural |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 119,558,000 | 233,512,000
Financing receivable originated one year prior to current fiscal year | 126,915,000 | 123,947,000
Financing receivable originated two years prior to current fiscal year | 86,893,000 | 60,744,000
Financing receivable originated three years prior to current fiscal year | 39,376,000 | 55,231,000
Financing receivable originated four years prior to current fiscal year | 19,329,000 | 32,545,000
Financing receivable originated five years or more prior to current fiscal year | 18,808,000 | 20,184,000
Revolving Loans | 397,057,000 | 364,460,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 807,936,000 | 890,623,000
Credit Quality Grades 1-6 | Solar |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 69,556,000 | 159,244,000
Financing receivable originated one year prior to current fiscal year | 115,921,000 | 42,073,000
Financing receivable originated two years prior to current fiscal year | 37,240,000 | 81,593,000
Financing receivable originated three years prior to current fiscal year | 72,710,000 | 18,979,000
Financing receivable originated four years prior to current fiscal year | 18,631,000 | 34,889,000
Financing receivable originated five years or more prior to current fiscal year | 33,467,000 | 3,780,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 347,525,000 | 340,558,000
Credit Quality Grades 1-6 | Auto and light truck |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 394,772,000 | 331,105,000
Financing receivable originated one year prior to current fiscal year | 186,699,000 | 122,709,000
Financing receivable originated two years prior to current fiscal year | 74,388,000 | 72,580,000
Financing receivable originated three years prior to current fiscal year | 41,687,000 | 24,965,000
Financing receivable originated four years prior to current fiscal year | 12,935,000 | 11,814,000
Financing receivable originated five years or more prior to current fiscal year | 4,713,000 | 901,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 715,194,000 | 564,074,000
Credit Quality Grades 1-6 | Medium and heavy duty truck |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 114,007,000 | 92,252,000
Financing receivable originated one year prior to current fiscal year | 72,478,000 | 68,354,000
Financing receivable originated two years prior to current fiscal year | 50,579,000 | 57,967,000
Financing receivable originated three years prior to current fiscal year | 38,281,000 | 23,210,000
Financing receivable originated four years prior to current fiscal year | 12,679,000 | 12,419,000
Financing receivable originated five years or more prior to current fiscal year | 4,986,000 | 5,265,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 293,010,000 | 259,467,000
Credit Quality Grades 1-6 | Aircraft |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 317,174,000 | 384,895,000
Financing receivable originated one year prior to current fiscal year | 292,885,000 | 290,897,000
Financing receivable originated two years prior to current fiscal year | 239,238,000 | 85,916,000
Financing receivable originated three years prior to current fiscal year | 60,565,000 | 45,848,000
Financing receivable originated four years prior to current fiscal year | 33,028,000 | 47,025,000
Financing receivable originated five years or more prior to current fiscal year | 47,775,000 | 29,435,000
Revolving Loans | 4,530,000 | 4,844,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 995,195,000 | 888,860,000
Credit Quality Grades 1-6 | Construction equipment |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 359,702,000 | 314,044,000
Financing receivable originated one year prior to current fiscal year | 234,401,000 | 201,032,000
Financing receivable originated two years prior to current fiscal year | 120,431,000 | 109,029,000
Financing receivable originated three years prior to current fiscal year | 68,480,000 | 47,693,000
Financing receivable originated four years prior to current fiscal year | 24,452,000 | 13,501,000
Financing receivable originated five years or more prior to current fiscal year | 7,729,000 | 5,031,000
Revolving Loans | 22,426,000 | 18,937,000
Revolving Loans Converted to Term | 2,975,000 | 4,594,000
Amortized cost of loans and leases | 840,596,000 | 713,861,000
Credit Quality Grades 1-6 | Commercial real estate |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 208,585,000 | 230,701,000
Financing receivable originated one year prior to current fiscal year | 170,211,000 | 150,144,000
Financing receivable originated two years prior to current fiscal year | 128,762,000 | 146,374,000
Financing receivable originated three years prior to current fiscal year | 115,556,000 | 141,838,000
Financing receivable originated four years prior to current fiscal year | 108,539,000 | 126,642,000
Financing receivable originated five years or more prior to current fiscal year | 189,259,000 | 112,243,000
Revolving Loans | 296,000 | 391,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 921,208,000 | 908,333,000
Credit Quality Grades 7-12 |  |
Loan and Lease Financings |  |
Relationships reviewed quarterly as part of management's evaluation of the appropriateness of the allowance for loan and lease losses | 250,000 |
Credit Quality Grades 7-12 | Commercial and agricultural |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 3,094,000 | 4,682,000
Financing receivable originated one year prior to current fiscal year | 2,897,000 | 194,000
Financing receivable originated two years prior to current fiscal year | 124,000 | 3,667,000
Financing receivable originated three years prior to current fiscal year | 2,358,000 | 2,373,000
Financing receivable originated four years prior to current fiscal year | 2,509,000 | 2,004,000
Financing receivable originated five years or more prior to current fiscal year | 1,399,000 | 484,000
Revolving Loans | 15,445,000 | 14,685,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 27,826,000 | 28,089,000
Credit Quality Grades 7-12 | Solar |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 0 | 0
Financing receivable originated one year prior to current fiscal year | 0 | 1,138,000
Financing receivable originated two years prior to current fiscal year | 1,103,000 | 5,882,000
Financing receivable originated three years prior to current fiscal year | 5,732,000 | 724,000
Financing receivable originated four years prior to current fiscal year | 705,000 | 0
Financing receivable originated five years or more prior to current fiscal year | 3,570,000 | 0
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 11,110,000 | 7,744,000
Credit Quality Grades 7-12 | Auto and light truck |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 6,569,000 | 10,828,000
Financing receivable originated one year prior to current fiscal year | 5,228,000 | 11,752,000
Financing receivable originated two years prior to current fiscal year | 7,419,000 | 7,467,000
Financing receivable originated three years prior to current fiscal year | 3,416,000 | 3,859,000
Financing receivable originated four years prior to current fiscal year | 2,511,000 | 4,876,000
Financing receivable originated five years or more prior to current fiscal year | 2,987,000 | 919,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 28,130,000 | 39,701,000
Credit Quality Grades 7-12 | Medium and heavy duty truck |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 0 | 0
Financing receivable originated one year prior to current fiscal year | 0 | 0
Financing receivable originated two years prior to current fiscal year | 0 | 0
Financing receivable originated three years prior to current fiscal year | 0 | 0
Financing receivable originated four years prior to current fiscal year | 0 | 0
Financing receivable originated five years or more prior to current fiscal year | 58,000 | 273,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 58,000 | 273,000
Credit Quality Grades 7-12 | Aircraft |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 592,000 | 1,141,000
Financing receivable originated one year prior to current fiscal year | 0 | 649,000
Financing receivable originated two years prior to current fiscal year | 578,000 | 0
Financing receivable originated three years prior to current fiscal year | 0 | 4,670,000
Financing receivable originated four years prior to current fiscal year | 0 | 454,000
Financing receivable originated five years or more prior to current fiscal year | 1,630,000 | 2,627,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 2,800,000 | 9,541,000
Credit Quality Grades 7-12 | Construction equipment |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 22,162,000 | 26,650,000
Financing receivable originated one year prior to current fiscal year | 9,618,000 | 8,709,000
Financing receivable originated two years prior to current fiscal year | 2,466,000 | 1,983,000
Financing receivable originated three years prior to current fiscal year | 2,081,000 | 797,000
Financing receivable originated four years prior to current fiscal year | 234,000 | 80,000
Financing receivable originated five years or more prior to current fiscal year | 55,000 | 0
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 1,480,000 | 2,193,000
Amortized cost of loans and leases | 38,096,000 | 40,412,000
Credit Quality Grades 7-12 | Commercial real estate |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 280,000 | 218,000
Financing receivable originated one year prior to current fiscal year | 838,000 | 5,921,000
Financing receivable originated two years prior to current fiscal year | 7,614,000 | 7,159,000
Financing receivable originated three years prior to current fiscal year | 6,138,000 | 491,000
Financing receivable originated four years prior to current fiscal year | 48,000 | 6,208,000
Financing receivable originated five years or more prior to current fiscal year | 1,297,000 | 1,011,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | 16,215,000 | 21,008,000
Performing | Residential real estate and home equity |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 89,237,000 | 105,345,000
Financing receivable originated one year prior to current fiscal year | 101,190,000 | 114,682,000
Financing receivable originated two years prior to current fiscal year | 101,388,000 | 41,185,000
Financing receivable originated three years prior to current fiscal year | 35,269,000 | 9,706,000
Financing receivable originated four years prior to current fiscal year | 7,274,000 | 11,720,000
Financing receivable originated five years or more prior to current fiscal year | 85,733,000 | 89,646,000
Revolving Loans | 142,535,000 | 122,281,000
Revolving Loans Converted to Term | 3,779,000 | 4,555,000
Amortized cost of loans and leases | 566,405,000 | 499,120,000
Performing | Consumer |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 59,856,000 | 58,866,000
Financing receivable originated one year prior to current fiscal year | 39,184,000 | 24,307,000
Financing receivable originated two years prior to current fiscal year | 15,115,000 | 17,031,000
Financing receivable originated three years prior to current fiscal year | 9,045,000 | 8,284,000
Financing receivable originated four years prior to current fiscal year | 3,854,000 | 2,263,000
Financing receivable originated five years or more prior to current fiscal year | 1,032,000 | 697,000
Revolving Loans | 20,323,000 | 21,378,000
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | $ 148,409,000 | 132,826,000
Nonperforming |  |
Loan and Lease Financings |  |
Classification of nonperforming loans, threshold period past due | 90 days |
Nonperforming | Residential real estate and home equity |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | $ 0 | 0
Financing receivable originated one year prior to current fiscal year | 186,000 | 0
Financing receivable originated two years prior to current fiscal year | 926,000 | 0
Financing receivable originated three years prior to current fiscal year | 0 | 13,000
Financing receivable originated four years prior to current fiscal year | 0 | 421,000
Financing receivable originated five years or more prior to current fiscal year | 669,000 | 655,000
Revolving Loans | 188,000 | 293,000
Revolving Loans Converted to Term | 228,000 | 88,000
Amortized cost of loans and leases | 2,197,000 | 1,470,000
Nonperforming | Consumer |  |
Loan and Lease Financings |  |
Financing receivable originated during current fiscal year | 0 | 37,000
Financing receivable originated one year prior to current fiscal year | 69,000 | 107,000
Financing receivable originated two years prior to current fiscal year | 30,000 | 43,000
Financing receivable originated three years prior to current fiscal year | 40,000 | 30,000
Financing receivable originated four years prior to current fiscal year | 15,000 | 33,000
Financing receivable originated five years or more prior to current fiscal year | 14,000 | 4,000
Revolving Loans | 0 | 0
Revolving Loans Converted to Term | 0 | 0
Amortized cost of loans and leases | $ 168,000 | $ 254,000

X
- Definition Direct finance lease term + References No definition available. + Details
Name: | source_DirectFinanceLeaseTerm
Namespace Prefix: | source_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expected life of underlying collateral + References No definition available. + Details
Name: | source_ExpectedLifeOfUnderlyingCollateral
Namespace Prefix: | source_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loan amortization period + References No definition available. + Details
Name: | source_LoanAmortizationPeriod
Namespace Prefix: | source_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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 of the appropriateness of the allowance for loan and lease losses. + References No definition available. + Details
Name: | source_LoansAndLeasesReceivableMinimumBalanceForEvaluationOfAllowanceForLoanAndLeaseLosses
Namespace Prefix: | source_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the number of methods to assess credit risk of loans and leases receivables. + References No definition available. + Details
Name: | source_LoansAndLeasesReceivableNumberOfMethodsToAssessCreditRisk
Namespace Prefix: | source_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the threshold period past due used to classify loans as nonperforming. + References No definition available. + Details
Name: | source_LoansAndLeasesReceivablePeriodPastDue
Namespace Prefix: | source_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of deferred interest and fee income and unamortized costs incurred to originate PPP loans. + References No definition available. + Details
Name: | source_LoansReceivableDeferredIncomePPPLoans
Namespace Prefix: | source_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of domestic aircraft loan pools + References No definition available. + Details
Name: | source_NumberOfDomesticAircraftLoanPools
Namespace Prefix: | source_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition PPP loan balance + References No definition available. + Details
Name: | source_PPPLoanBalance
Namespace Prefix: | source_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Period of amortization to reach equity position in collateral + References No definition available. + Details
Name: | source_PeriodOfAmortizationToReachEquityPositionInCollateral
Namespace Prefix: | source_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated in current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost of financing receivable that can be withdrawn, repaid, and redrawn. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableRevolving
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of revolving financing receivable converted to term loan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6A -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120270059-210447 + Details
Name: | us-gaap_FinancingReceivableRevolvingConvertedToTermLoan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524 + Details
Name: | us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=source_CommercialAndAgriculturalLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=source_SolarLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=source_AutoAndLightTruckMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=source_MediumAndHeavyDutyTruckMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=source_AircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=source_ConstructionEquipmentFinancingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_ConsumerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=source_InternallyAssignedGrade1To6Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=source_InternallyAssignedGrade7To12Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |