XML 102 R93.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stock-Based Incentive Plans - Summary of Stock Options Granted and Outstanding (Detail)
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding 318,901us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 299,107us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 350,642us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 565,615us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Price Range One [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding 318,901us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeOneMember		      
Price Range One [Member] | Incentive [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding 111,605us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_StockCompensationPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeOneMember		      
Price Range One [Member] | Nonqualified [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding 207,296us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= snbc_NonQualifiedMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeOneMember		      
Price Range Two [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding   299,107us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeTwoMember		    
Price Range Two [Member] | Incentive [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding   112,546us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_StockCompensationPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeTwoMember		    
Price Range Two [Member] | Nonqualified [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding   186,561us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= snbc_NonQualifiedMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeTwoMember		    
Price Range Three [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding     350,642us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeThreeMember		  
Price Range Three [Member] | Incentive [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding     160,630us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_StockCompensationPlanMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeThreeMember		  
Price Range Three [Member] | Nonqualified [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted and outstanding     190,012us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= snbc_NonQualifiedMember
/ us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis
= snbc_PriceRangeThreeMember