EMPLOYEE BENEFIT PLANS (Details Textual) (USD $)	12 Months Ended															12 Months Ended							3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Director [Member]	Dec. 31, 2011 Director [Member]	Dec. 31, 2010 Director [Member]	Dec. 31, 2012 Other Postretirement Benefit Plans, Defined Benefit [Member] age	Dec. 31, 2011 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2010 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2012 Supplemental Executive Retirement Plans [Member]	Dec. 31, 2011 Supplemental Executive Retirement Plans [Member]	Dec. 31, 2010 Supplemental Executive Retirement Plans [Member]	Dec. 31, 2009 Supplemental Executive Retirement Plans [Member]	Dec. 31, 2012 Supplemental Executive Retirement Plans [Member] Trading Securities [Member]	Dec. 31, 2011 Supplemental Executive Retirement Plans [Member] Trading Securities [Member]	Dec. 31, 2012 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member]	Dec. 31, 2011 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member]	Dec. 31, 2010 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member]	Dec. 31, 2012 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member] Maximum [Member]	Dec. 31, 2012 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member] 2012-2013 [Member]	Dec. 31, 2011 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member] 2012-2013 [Member]	Dec. 31, 2010 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member] 2012-2013 [Member]	Mar. 12, 2013 Pension Plan [Member] Pentegra Defined Benefit Plan for Financial Institutions [Member] Subsequent Event [Member] 2012-2013 [Member]
Multiemployer Plans [Abstract]
Significance of contributions percentage																			5.00%
Cash payment																$ 234,000	$ 2,217,000	$ 1,794,000		$ 234,000			$ 841,000
Defined benefit plan expense										1,144,000	794,000	757,000				1,600,000	1,900,000	1,600,000
Postretirement Benefits [Abstract]
Retirement age							65
Service period to be eligible for postretirement benefit							10 years
Death benefit							5,000
Postretirement benefit expense							82,000	46,000	281,000
Supplemental Executive Retirement Plans [Abstract]
Plan assets														6,700,000	5,000,000
Estimated future employer contributions in next fiscal year										247,000
Incentive plans and discretionary bonus expense	7,800,000	7,800,000	6,900,000
Defined Contribution Plan [Abstract]
Employer matching contribution percent	25.00%
Employee contribution percent	6.00%
Nondiscretionary requisite service period	1 year
Nondiscretionary employer contribution, percent up to social security limit	5.00%
Nondiscretionary employer contribution, percent over social security limit	10.00%
Defined contribution plan expense	3,600,000	3,400,000	3,200,000
Deferred Compensation Arrangements [Abstract]
Deferred compensation deferred				88,000	136,000	160,000
Deferred compensation, shares provided for the plan (in shares)				179,814	180,058
Deferred compensation, recorded liability				$ 3,200,000	$ 3,000,000