CORRECTION OF PRIOR PERIOD ERROR (Narrative) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended				3 Months Ended	9 Months Ended	12 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2011 ScenarioPreviouslyReportedMember	Sep. 30, 2011 ScenarioPreviouslyReportedMember	Dec. 31, 2011 ScenarioPreviouslyReportedMember	Dec. 31, 2010 ScenarioPreviouslyReportedMember	Sep. 30, 2011 RestatementAdjustmentMember	Sep. 30, 2011 RestatementAdjustmentMember	Dec. 31, 2011 RestatementAdjustmentMember	Dec. 31, 2010 RestatementAdjustmentMember	Dec. 31, 2011 Restatement Adjustment Noncumulative [Member]
Net earnings	$ 11,299	$ 34,493	$ 75,351	$ 88,225			$ 34,360	$ 90,672	$ 130,000		$ 133	$ (2,447)	$ (4,000)
Retained earnings	$ 1,227,191		$ 1,227,191		$ 1,164,041	$ 1,053,000			$ 1,187,989	$ 1,072,000			$ (23,948)	$ 19,000	$ (23,000)