Loans (Details 2) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Grades 1, 3, 6 and 7    
Loans    
Loans receivable $ 2,280,000,000 $ 2,120,000,000
Increase or decrease in loans receivable 160,900,000  
Grades 8, 9, and 10    
Loans    
Loans receivable 124,000,000 161,900,000
Increase or decrease in loans receivable (37,900,000)  
Grades 1,3,6    
Loans    
Loans receivable 2,133,254,000 1,928,794,000
Grades 1,3,6 | Illinois/Indiana    
Loans    
Loans receivable 1,896,770,000 1,710,039,000
Grades 1,3,6 | Florida    
Loans    
Loans receivable 236,484,000 218,755,000
Grade 7    
Loans    
Loans receivable 145,154,000 188,741,000
Grade 7 | Illinois/Indiana    
Loans    
Loans receivable 107,843,000 152,084,000
Grade 7 | Florida    
Loans    
Loans receivable 37,311,000 36,657,000
Grade 8    
Loans    
Loans receivable 66,605,000 77,253,000
Grade 8 | Illinois/Indiana    
Loans    
Loans receivable 50,309,000 52,625,000
Grade 8 | Florida    
Loans    
Loans receivable 16,296,000 24,628,000
Grade 9    
Loans    
Loans receivable 48,438,000 67,531,000
Grade 9 | Illinois/Indiana    
Loans    
Loans receivable 29,702,000 50,240,000
Grade 9 | Florida    
Loans    
Loans receivable 18,736,000 17,291,000
Grade 10    
Loans    
Loans receivable 9,000,000 17,164,000
Grade 10 | Illinois/Indiana    
Loans    
Loans receivable 5,299,000 13,370,000
Grade 10 | Florida    
Loans    
Loans receivable 3,701,000 3,794,000
Commercial    
Loans    
Limit above which loans are processed through an expedited underwriting process 1,000,000  
Limit above which loans are annually reviewed 1,000,000  
Commercial | Illinois/Indiana    
Loans    
Weighted Avg. Risk Grade 4.80 4.66
Commercial | Florida    
Loans    
Weighted Avg. Risk Grade 5.40 5.89
Commercial | Grades 1,3,6    
Loans    
Limit above which loans are processed through an expedited underwriting process 350,000  
Commercial | Grades 1,3,6 | Minimum    
Loans    
Limit above which loans are processed through an expedited underwriting process 350,000  
Commercial | Grades 1,3,6 | Maximum    
Loans    
Limit above which loans are processed through an expedited underwriting process 1,000,000  
Commercial | Grades 1,3,6 | Illinois/Indiana    
Loans    
Loans receivable 542,796,000 487,587,000
Commercial | Grades 1,3,6 | Florida    
Loans    
Loans receivable 13,455,000 16,460,000
Commercial | Grade 7    
Loans    
Limit above which loans are processed through an expedited underwriting process 1,000,000  
Limit above which loans are annually reviewed 1,000,000  
Commercial | Grade 7 | Illinois/Indiana    
Loans    
Loans receivable 27,032,000 46,992,000
Commercial | Grade 7 | Florida    
Loans    
Loans receivable 105,000 174,000
Commercial | Grade 8    
Loans    
Limit above which loans are annually reviewed 1,000,000  
Commercial | Grade 8 | Illinois/Indiana    
Loans    
Loans receivable 8,549,000 15,986,000
Commercial | Grade 8 | Florida    
Loans    
Loans receivable 78,000 3,218,000
Commercial | Grade 9 | Illinois/Indiana    
Loans    
Loans receivable 5,498,000 8,536,000
Commercial | Grade 9 | Florida    
Loans    
Loans receivable 1,459,000 684,000
Commercial | Grade 10 | Illinois/Indiana    
Loans    
Loans receivable 1,146,000 975,000
Commercial | Grade 10 | Florida    
Loans    
Loans receivable 1,642,000  
Commercial real estate | Illinois/Indiana    
Loans    
Weighted Avg. Risk Grade 5.67 5.55
Commercial real estate | Florida    
Loans    
Weighted Avg. Risk Grade 6.00 6.02
Commercial real estate | Grades 1,3,6 | Illinois/Indiana    
Loans    
Loans receivable 819,708,000 799,117,000
Commercial real estate | Grades 1,3,6 | Florida    
Loans    
Loans receivable 123,807,000 116,741,000
Commercial real estate | Grade 7 | Illinois/Indiana    
Loans    
Loans receivable 64,975,000 79,371,000
Commercial real estate | Grade 7 | Florida    
Loans    
Loans receivable 25,520,000 16,470,000
Commercial real estate | Grade 8 | Illinois/Indiana    
Loans    
Loans receivable 25,719,000 19,327,000
Commercial real estate | Grade 8 | Florida    
Loans    
Loans receivable 6,002,000 11,250,000
Commercial real estate | Grade 9 | Illinois/Indiana    
Loans    
Loans receivable 19,821,000 29,606,000
Commercial real estate | Grade 9 | Florida    
Loans    
Loans receivable 15,404,000 12,721,000
Commercial real estate | Grade 10 | Illinois/Indiana    
Loans    
Loans receivable 2,685,000 4,597,000
Commercial real estate | Grade 10 | Florida    
Loans    
Loans receivable 510,000 3,073,000
Real estate construction | Illinois/Indiana    
Loans    
Weighted Avg. Risk Grade 5.91 7.11
Real estate construction | Florida    
Loans    
Weighted Avg. Risk Grade 6.21 6.64
Real estate construction | Grades 1,3,6 | Illinois/Indiana    
Loans    
Loans receivable 71,074,000 21,585,000
Real estate construction | Grades 1,3,6 | Florida    
Loans    
Loans receivable 16,475,000 7,886,000
Real estate construction | Grade 7 | Illinois/Indiana    
Loans    
Loans receivable 5,332,000 16,376,000
Real estate construction | Grade 7 | Florida    
Loans    
Loans receivable   7,961,000
Real estate construction | Grade 8 | Illinois/Indiana    
Loans    
Loans receivable 11,448,000 11,920,000
Real estate construction | Grade 8 | Florida    
Loans    
Loans receivable 615,000 743,000
Real estate construction | Grade 9 | Illinois/Indiana    
Loans    
Loans receivable 1,204,000 7,686,000
Real estate construction | Grade 9 | Florida    
Loans    
Loans receivable 842,000 836,000
Real estate construction | Grade 10 | Illinois/Indiana    
Loans    
Loans receivable 46,000 3,862,000
Real estate construction | Grade 10 | Florida    
Loans    
Loans receivable 18,000  
Retail real estate | Illinois/Indiana    
Loans    
Weighted Avg. Risk Grade 3.46 3.53
Retail real estate | Florida    
Loans    
Weighted Avg. Risk Grade 4.09 3.85
Retail real estate | Grades 1,3,6 | Illinois/Indiana    
Loans    
Loans receivable 453,560,000 393,299,000
Retail real estate | Grades 1,3,6 | Florida    
Loans    
Loans receivable 82,185,000 77,116,000
Retail real estate | Grade 7 | Illinois/Indiana    
Loans    
Loans receivable 10,478,000 9,285,000
Retail real estate | Grade 7 | Florida    
Loans    
Loans receivable 11,686,000 12,052,000
Retail real estate | Grade 8 | Illinois/Indiana    
Loans    
Loans receivable 4,569,000 5,392,000
Retail real estate | Grade 8 | Florida    
Loans    
Loans receivable 9,601,000 9,417,000
Retail real estate | Grade 9 | Illinois/Indiana    
Loans    
Loans receivable 3,179,000 4,408,000
Retail real estate | Grade 9 | Florida    
Loans    
Loans receivable 1,031,000 3,050,000
Retail real estate | Grade 10 | Illinois/Indiana    
Loans    
Loans receivable 1,414,000 3,936,000
Retail real estate | Grade 10 | Florida    
Loans    
Loans receivable 1,531,000 721,000
Retail other | Illinois/Indiana    
Loans    
Weighted Avg. Risk Grade 3.21 2.64
Retail other | Florida    
Loans    
Weighted Avg. Risk Grade 2.94 1.72
Retail other | Grades 1,3,6 | Illinois/Indiana    
Loans    
Loans receivable 9,632,000 8,451,000
Retail other | Grades 1,3,6 | Florida    
Loans    
Loans receivable 562,000 552,000
Retail other | Grade 7 | Illinois/Indiana    
Loans    
Loans receivable 26,000 60,000
Retail other | Grade 8 | Illinois/Indiana    
Loans    
Loans receivable 24,000  
Retail other | Grade 9 | Illinois/Indiana    
Loans    
Loans receivable   4,000
Retail other | Grade 10 | Illinois/Indiana    
Loans    
Loans receivable $ 8,000