Derivatives (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Notional Amount	$ 8,918,418
Asset	80,000
Liability	80,000
Life	14 years 10 months 24 days
Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount	5,155,000	5,155,000
Asset	0	0
Liability	461,000	314,000
Receive Rate (in hundredths)	0.32%	0.29%
Pay Rate (in hundredths)	2.59%	2.59%
Life	7 years 9 months 18 days	8 years 9 months 18 days
Pay fixed - receive floating interest rate swap [Member] | Hedging Instrument [Member]
Derivative [Line Items]
Fair value of hedge agreement	(461,000)	(314,000)
Amounts included in accumulated other comprehensive income as unrealized losses	(304,000)	(208,000)
Number of positions	1	1
Notional Amount	5,155,000	5,155,000
Asset	0	0
Liability	461,000	314,000
Receive Rate (in hundredths)	0.32%	0.29%
Pay Rate (in hundredths)	2.59%	2.59%
Life	7 years 9 months 18 days	8 years 9 months 18 days
Interest rate lock commitments related to mandatory delivery methods [Member] | Hedging Instrument [Member]
Derivative [Line Items]
Fair value of hedge agreement	35,000
Number of positions	41
Notional Amount	8,800,000	0
Forward sales contracts of MBS [Member] | Hedging Instrument [Member]
Derivative [Line Items]
Fair value of hedge agreement	39,000
Number of positions	11
Notional Amount	9,100,000	0
Open best efforts interest rate lock commitments [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount	93,800,000	90,400,000
Open forward sales commitments to investors [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount	167,200,000	182,900,000
Pay fixed receive floating rate interest rate swap [Member]
Derivative [Line Items]
Number of positions	1
Notional Amount	4,459,209
Asset	0
Liability	80,000
Variable rate basis	LIBOR
Spread on variable rate (in hundredths)	20.00%
Pay Rate (in hundredths)	3.90%
Life	14 years 10 months 24 days
Pay floating receive floating rate interest rate swap [Member]
Derivative [Line Items]
Number of positions	1
Notional Amount	4,459,209
Asset	$ 80,000
Receive Rate (in hundredths)	3.90%
Variable rate basis	LIBOR
Spread on variable rate (in hundredths)	20.00%
Life	14 years 10 months 24 days