STOCKHOLDERS' EQUITY (Details 2) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Y	Sep. 30, 2010	Dec. 31, 2010 Y
Employee stock incentive plans
Award vesting period (in years)	5Y
Term of award (in years)	10Y
Options activity outstanding of stock option plan
Exercised (in shares)	(3,000)	(180,000)	(56,000)	(418,000)
Aggregate Intrinsic Value
Cash receipts from options exercised			$ 19,000	$ 251,000
Tax benefits from share-based payments			2,300,000	1,000,000
Time Lapse Restricted Shares [Member]
Employee stock incentive plans
Pre-tax compensation expense	1,882,000	1,638,000	5,645,000	5,859,000
Tax benefit	(725,000)	(631,000)	(2,174,000)	(2,256,000)
Restricted stock expense, net of tax	1,157,000	1,007,000	3,471,000	3,603,000
Weighted-Average Grant-Date Fair Value
Unrecognized compensation cost	26,500,000		26,500,000		22,100,000
Unrecognized compensation cost, period for recognition (in years)			4.2		3.9
Restricted Stock Units
Unvested restricted stock activity
Balance outstanding at the beginning of the period (in shares)			2,664,000
Forfeited (in shares)			(65,000)
Vested (in shares)			(573,000)
Granted (in shares)			670,000
Balance outstanding at the end of the period (in shares)	2,696,000		2,696,000
Weighted-Average Grant-Date Fair Value
Balance at the beginning of the period (in dollars per share)			$ 11.09
Forfeited (in dollars per share)	$ 12.50		$ 12.50
Vested (in dollars per share)			$ 10.08
Granted (in dollars per share)			$ 19.30
Balance at the end of the period (in dollars per share)	$ 13.32		$ 13.32
Stock options
Options activity outstanding of stock option plan
Balance outstanding at the beginning of the period (in shares)			136,000
Exercised (in shares)			(56,000)
Balance outstanding at the end of the period (in shares)	80,000		80,000
Exercisable (in shares)	80,000		80,000
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)			$ 4.66
Exercised (in dollars per share)	$ 4.22		$ 4.22
Balance at the end of the period (in dollars per share)	$ 4.98		$ 4.98
Exercisable (in dollars per share)	$ 4.98		$ 4.98
Weighted-Average Remaining Contractual Term (in years)
Balance at the beginning of the period (in years)			1.59
Balance at the end of the period (in years)	1.02		1.02
Exercisable (in years)			1.02
Aggregate Intrinsic Value
Balance at the beginning of the period			2,056,000
Exercised			200,000	4,000,000
Balance at the end of the period	1,100,000		1,100,000
Exercisable	1,100,000		1,100,000
Cash receipts from options exercised			$ 19,000	$ 300,000