EARNINGS PER SHARE (NVE) (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Numerator
Net income	$ 173,462,000		$ 177,546,000	[1]	$ 188,680,000		$ 212,771,000	[1]
Denominator
Weighted average number of common shares outstanding (in shares)	235,990,373		235,117,058		235,796,321		234,991,208
Per Share Amounts
Net income per share - basic	$ 0.74		$ 0.76	[1]	$ 0.80		$ 0.91	[1]
Numerator
Net Income (Loss)	173,462,000		177,546,000	[1]	188,680,000		212,771,000	[1]
Denominator
Weighted average number of common shares outstanding (in shares)	235,990,373		235,117,058		235,796,321		234,991,208
Stock options	33,343		35,973		36,314		30,818
Non-Employee Director stock plan (in shares)	141,122		147,718		142,587		137,032
Employee stock purchase plan (in shares)	4,012		9,463		4,547		6,186
Restricted Shares (in shares)	146,464		87,613		123,940		69,322
Performance Shares (in shares)	1,586,016		1,079,362		1,217,087		902,159
Weighted average number of shares outstanding after dilution (in shares)	237,901,330	[2]	236,477,187	[2]	237,320,796	[2]	236,136,725	[2]
Per Share Amounts
Net income per share - diluted	$ 0.73		$ 0.75	[1]	$ 0.80		$ 0.90	[1]
Excluded stock equivalents for options issued under the non-qualified stock option plan (in shares)	572,825		701,190		575,846		707,950
Schedule Of Prior Period Adjustment [Line Items]
Net income, net of taxes	173,462,000		177,546,000	[1]	188,680,000		212,771,000	[1]
Revision Adjustment [Member]
Numerator
Net income			(5,200,000)				(5,200,000)
Numerator
Net Income (Loss)			(5,200,000)				(5,200,000)
Schedule Of Prior Period Adjustment [Line Items]
Net income, net of taxes			$ (5,200,000)				$ (5,200,000)
Basic and diluted earnings per share, net of taxes (in dollars per share)			$ (0.02)				$ (0.02)

[1] As discussed in Note 1, Summary of Significant Accounting Policies, net income and earnings per share basic and diluted were reduced from that previously reported by $5.2 million (net of taxes) and $0.02 per share (net of taxes), respectively.

[2] The denominator does not include stock equivalents for options issued under the non-qualified stock option plan due to conversion prices being higher than market prices for all periods. If the conditions for conversion were met under this plan, 572,825 and 575,846 shares would be included for the three and nine months ended September 30, 2011, and 701,190 and 707,950 would be included for the three and nine months ended September 30, 2010, respectively.