Debt (Principal Payments Of Debt) (Details) (USD $)	9 Months Ended
	Sep. 30, 2011
Debt Instrument [Line Items]
2011 remaining	$ 8,109,000
2012	507,195,000
2013	315,094,000
2014	473,863,000
2015	245,603,000
2016	231,311,000
2017	142,119,000
2018	64,411,000
2019	153,747,000
2020	3,658,000
Thereafter	121,129,000	[1]
Total	2,266,239,000
3.95 % Convertible Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Convertible senior unsecured notes	$ 54,100,000
Debt instrument stated interest percentage	3.95%
Debt maturity date	2026

[1] Includes $54.1 million of our 3.95% convertible senior unsecured notes outstanding due 2026, which may be called by us at any time and have future put options in 2016 and 2021.