EARNINGS PER SHARE (NVE) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Numerator
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (25,248)	$ 173,462	$ 12,888	$ 2,330	$ 14,213	$ 177,546	$ 36,946	$ (1,721)	$ 163,432		$ 226,984		$ 182,936
Denominator
Weighted Average Shares of Common Stock Outstanding - basic									235,847,596		235,048,347		234,542,292
Per Share Amounts
Net income per share - basic	$ (0.11)	$ 0.74	$ 0.05	$ 0.01	$ 0.06	$ 0.76	$ 0.16	$ (0.01)	$ 0.69		$ 0.97		$ 0.78
Numerator
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (25,248)	$ 173,462	$ 12,888	$ 2,330	$ 14,213	$ 177,546	$ 36,946	$ (1,721)	$ 163,432		$ 226,984		$ 182,936
Denominator
Weighted Average Number of Shares Outstanding, Basic									235,847,596		235,048,347		234,542,292
Stock options (in shares)									36,189		34,590		27,596
Non-Employee Director stock plan (in shares)									143,791		141,577		100,244
Employee stock purchase plan (in shares)									4,111		5,909		7,331
Restricted Shares (in shares)									395,813		78,920		12,389
Performance Shares (in shares)									1,339,571		985,469		490,836
Weighted Average Number of Shares Outstanding, Diluted									237,767,071	[1]	236,294,812	[1]	235,180,688	[1]
Per Share Amounts
Net income per share - diluted	$ (0.11)	$ 0.73	$ 0.05	$ 0.01	$ 0.06	$ 0.75	$ 0.16	$ (0.01)	$ 0.69		$ 0.96		$ 0.78
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									557,793		701,658		679,272

[1] The denominator does not include stock equivalents for options issued under the LTIP due to conversion prices being higher than market prices for all periods. Under this plan, an additional 557,793, 701,658 and 679,272 shares for 2011, 2010 and 2009, respectively, would be included in each of these periods if the conditions for conversion were met.