Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Cash and cash equivalents policy disclosures
Federal Reserve System Cash Reserve Requirement	$ 37,700,000	$ 37,700,000
Loans receivable and allowance for loan losses policy disclosures
Period of time after which we discontinue accruing interest on loans	90 days
Period of time in non-accrual status for restructured loans to demonstrate performance	6 months
Minimum threshold of combined outstanding balances reviewed annually for borrowing relationships to one borrower	5,000,000
Portion of outstanding principal balance of the loans to a single borrowing entity which will be reviewed by the Asset Review Department	50.00%
Length of period one over which the historical loss experience is analyzed	12 months
Length of period two over which the historical loss experience is analyzed	15 months
Length of period three over which the historical loss experience is analyzed	18 months
Length of period four over which the historical loss experience is analyzed	24 months
Minimum length of period over which the historical loss experience is analyzed for a particular loan type that may not have sufficient loss history	2 years
Extended prior period over which loss experience factors are evaluated to consider trends for the majority of loan portfolio	2 years
Premises and equipment policy disclosures
Accumulated depreciation and amortization of premises and equipment	194,100,000	184,600,000
Goodwill policy
Goodwill	185,151,000	185,151,000
Goodwill impairment	0
Bank owned life insurance policy
Bank owned life insurance, cash surrender value	395,800,000	394,100,000
Bank owned life insurance, stabilization reserve	27,600,000	24,100,000
Bank owned life insurance, deferred acquisition costs	1,000	2,000
Real estate owned policy
Real estate owned, valuation allowance for losses	834,000	1,600,000
Earnings Per Common Share
Unallocated common stock held by ESOP, shares	0	967,013
Residential mortgage loans
Loans receivable and allowance for loan losses policy disclosures
Period after which loans are individually evaluated for impairment	180 days
Multi Family and Commercial Real Estate Mortgage Loan | Minimum
Loans receivable and allowance for loan losses policy disclosures
Threshold for loan balances individually reviewed	5,000,000
Multi Family and Commercial Real Estate Mortgage Loan | Maximum
Loans receivable and allowance for loan losses policy disclosures
Loans further reviewed by portfolio management personnel	5,000,000
Commercial loans | Minimum
Loans receivable and allowance for loan losses policy disclosures
Threshold for loan balances individually reviewed	$ 500,000