XML 47 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9
LOANS, Summary of Impaired Loans (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Summary of impaired loans [Abstract]      
Impaired loans with no allowance recorded, Unpaid Principal Balance $ 18,624us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance $ 22,171us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance  
Impaired loans with an allowance recorded, Unpaid Principal Balance 4,474us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance 4,518us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance  
Impaired loans, Unpaid Principal Balance, Total 23,098us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance 26,689us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance  
Impaired loans with no allowance recorded, Recorded Investment 18,077us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment 21,608us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment  
Impaired loans with an allowance recorded, Recorded Investment 4,338us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment 4,382us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment  
Impaired Loans, Recorded Investment, Total 22,415us-gaap_ImpairedFinancingReceivableRecordedInvestment 25,990us-gaap_ImpairedFinancingReceivableRecordedInvestment  
Impaired Loans, No Allowance Allocated 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance  
Impaired Loans, Allowance Allocated 1,005us-gaap_ImpairedFinancingReceivableRelatedAllowance 945us-gaap_ImpairedFinancingReceivableRelatedAllowance  
Average recorded investment in impaired loans 23,930us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 30,128us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 87,947us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Interest income recognized on impaired loans 1,289us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 2,094us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod 1,498us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Commercial and Industrial [Member]      
Summary of impaired loans [Abstract]      
Impaired loans with no allowance recorded, Unpaid Principal Balance 4,833us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
6,711us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
 
Impaired loans with an allowance recorded, Unpaid Principal Balance 57us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
1,043us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
 
Impaired loans with no allowance recorded, Recorded Investment 4,833us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
6,711us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
 
Impaired loans with an allowance recorded, Recorded Investment 56us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
1,043us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
 
Impaired Loans, No Allowance Allocated 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
 
Impaired Loans, Allowance Allocated 16us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
41us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
 
Average recorded investment in impaired loans 6,961us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
12,065us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
23,215us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
Interest income recognized on impaired loans 730us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
800us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
447us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialLoanMember
Commercial Real Estate [Member]      
Summary of impaired loans [Abstract]      
Impaired loans with no allowance recorded, Unpaid Principal Balance 10,632us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
12,239us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Impaired loans with no allowance recorded, Recorded Investment 10,214us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
11,821us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Impaired Loans, No Allowance Allocated 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
 
Average recorded investment in impaired loans 10,823us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
11,556us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
38,477us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Interest income recognized on impaired loans 251us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
1,041us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
501us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Real Estate Construction [Member]      
Summary of impaired loans [Abstract]      
Average recorded investment in impaired loans 0us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= subk_RealEstateConstructionPortfolioSegmentMember
488us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= subk_RealEstateConstructionPortfolioSegmentMember
13,681us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= subk_RealEstateConstructionPortfolioSegmentMember
Interest income recognized on impaired loans 0us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= subk_RealEstateConstructionPortfolioSegmentMember
114us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= subk_RealEstateConstructionPortfolioSegmentMember
410us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= subk_RealEstateConstructionPortfolioSegmentMember
Residential Mortgages [Member]      
Summary of impaired loans [Abstract]      
Impaired loans with no allowance recorded, Unpaid Principal Balance 1,645us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2,305us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
 
Impaired loans with an allowance recorded, Unpaid Principal Balance 3,906us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2,873us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
 
Impaired loans with no allowance recorded, Recorded Investment 1,516us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2,176us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
 
Impaired loans with an allowance recorded, Recorded Investment 3,906us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
2,873us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
 
Impaired Loans, No Allowance Allocated 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
 
Impaired Loans, Allowance Allocated 809us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
709us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
 
Average recorded investment in impaired loans 5,094us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
4,970us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
9,538us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Interest income recognized on impaired loans 207us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
102us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
127us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialPortfolioSegmentMember
Home Equity [Member]      
Summary of impaired loans [Abstract]      
Impaired loans with no allowance recorded, Unpaid Principal Balance 1,377us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
891us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
 
Impaired loans with an allowance recorded, Unpaid Principal Balance 326us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
328us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
 
Impaired loans with no allowance recorded, Recorded Investment 1,377us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
891us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
 
Impaired loans with an allowance recorded, Recorded Investment 190us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
191us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
 
Impaired Loans, No Allowance Allocated 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
 
Impaired Loans, Allowance Allocated 92us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
93us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
 
Average recorded investment in impaired loans 804us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
814us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
2,607us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
Interest income recognized on impaired loans 83us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
15us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
13us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
Consumer [Member]      
Summary of impaired loans [Abstract]      
Impaired loans with no allowance recorded, Unpaid Principal Balance 137us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
25us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Impaired loans with an allowance recorded, Unpaid Principal Balance 185us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
274us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Impaired loans with no allowance recorded, Recorded Investment 137us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
9us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Impaired loans with an allowance recorded, Recorded Investment 186us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
275us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Impaired Loans, No Allowance Allocated 0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
0subk_ImpairedFinancingReceivableWithNoRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Impaired Loans, Allowance Allocated 88us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
102us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
 
Average recorded investment in impaired loans 248us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
235us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
429us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
Interest income recognized on impaired loans $ 18us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
$ 22us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember
$ 0us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerPortfolioSegmentMember