Debt (Carrying Value Of Long-Term Debt Of Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009
Senior notes	$ 1,631,861	$ 1,640,638
Other long-term borrowings	36,988	37,528
Total long-term debt	1,668,849	1,678,166
$500 million, 6.45% due June 1, 2016 [Member]
Senior notes	500,000
Senior note interest rate	6.45%
Senior note, carrying amount	535,342	540,907
Debt instrument, maturity date	Jun. 01, 2016
$500 Million, 7.20% Due June 15, 2018 [Member]
Senior notes	500,000
Senior note interest rate	7.20%
Senior note, carrying amount	508,005	508,799
Debt instrument, maturity date	Jun. 15, 2018
$300 million, 6.30% due August 1, 2018 [Member]
Senior notes	300,000
Senior note interest rate	6.30%
Senior note, carrying amount	321,622	323,862
Debt instrument, maturity date	Aug. 01, 2018
$250 Million, 8.15% Due June 15, 2038 [Member]
Senior notes	250,000
Senior note interest rate	8.15%
Senior note, carrying amount	$ 266,892	$ 267,070
Debt instrument, maturity date	Jun. 15, 2038

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Interest rate stated in the contractual debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

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Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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