SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011 point	Dec. 31, 2011	Dec. 31, 2010
RETROSPECTIVE ACCOUNTING STANDARDS
Reduction of deferred policy acquisition costs asset	$ (51,655,000)		$ (52,105,000)
Decrease in consolidated shareholders equity	(828,677,000)		(792,634,000)
Increase (Decrease) in net income	28,038,000	27,706,000
Additional diluted earnings per share	$ 1.30	$ 1.30
Accounting Standards Update 2010-26 | Restatement Adjustment
RETROSPECTIVE ACCOUNTING STANDARDS
Reduction of deferred policy acquisition costs asset			40,300,000
Decrease in consolidated shareholders equity			26,200,000	22,200,000
Deferred income tax expense (benefit)			14,100,000
Additional diluted earnings per share			$ 0.06
Reduction in book value per share			$ 1.24	$ 1.06
Increase (decrease) in policy acquisition costs	1,600,000	(1,900,000)
Reduction to revised combined ratio		1.6
Increase (decrease) in net earnings per share	$ (0.05)	$ 0.06
Increase in revised net earnings		$ 1,200,000