Investment and Mortgage-Backed Securities, Available for Sale (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014 security	Jun. 30, 2013	Jun. 30, 2014 security	Jun. 30, 2013	Dec. 31, 2013 security
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	$ 428,932,644		$ 428,932,644		$ 430,241,854
Available-for-sale Securities, Fair Value Disclosure	436,810,833		436,810,833		431,003,452
Available For Sale Securities Pledged as Collateral, Amortized Cost Basis	129,000,000		129,000,000		118,300,000
Available-for-sale Securities Pledged as Collateral, Fair Value	132,800,000		132,800,000		121,100,000
Proceeds From Sale of Available For Sale Securities Including Mortgage Backed Securities	13,400,000	10,900,000	27,300,000	31,800,000
Percent of unrealized losses for securities in a continuous loss position for 12 months or more	11.40%		11.40%
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	38		38		11
Available-for-sale Securities, Gross Realized Losses	207,000	0	432,000	0
GNMA Mortgage-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost of Investment And Mortgage-Backed Securities Available For Sale	172,600,000		172,600,000		170,400,000
Available-for-sale Securities, Fair Value Disclosure	177,200,000		177,200,000		173,500,000
Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Realized Gains	$ 168,000	$ 370,000	$ 477,000	$ 754,000