Loans Receivable, Part I (Details) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Mortgage Loans [Abstract]      
Loans receivable $ 1,092,676,000 $ 1,133,672,000  
Percentage of total loans receivable secured by residential real estate (in hundredths) 88.80%    
Mortgage loans receivable located outside the state of Wisconsin 60,300,000    
Percentage of total mortgage loans located outside of the state of Wisconsin (in hundredths) 5.50%    
Loans originated for sale 1,751,054,000 1,749,426,000 1,027,346,000
Proceeds on sales of loans originated for sale 1,861,194,000 1,794,268,000 1,072,863,000
Noninterest income 80,260,000 87,375,000 39,845,000
Loans sold on a servicing retained basis 563,700,000 635,800,000  
Loans receivable pledged as collateral 882,900,000 801,600,000  
Advances by Federal Home Loan Bank 350,000,000 350,000,000  
One-to Four-family [Member]
     
Mortgage Loans [Abstract]      
Loans receivable 413,614,000 460,821,000  
Over Four-Family [Member]
     
Mortgage Loans [Abstract]      
Loans receivable 521,597,000 514,363,000  
Home Equity [Member]
     
Mortgage Loans [Abstract]      
Loans receivable 35,432,000 36,494,000  
Construction and Land [Member]
     
Mortgage Loans [Abstract]      
Loans receivable 31,905,000 33,818,000  
Commercial Real Estate [Member]
     
Mortgage Loans [Abstract]      
Loans receivable 71,698,000 65,495,000  
Consumer [Member]
     
Mortgage Loans [Abstract]      
Loans receivable 134,000 132,000  
Commercial Loans [Member]
     
Mortgage Loans [Abstract]      
Loans receivable $ 18,296,000 $ 22,549,000