Segment And Geographic Information (Reconciliation Of Total Segment Income From Operations To Consolidated Income Before Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting [Abstract]
Income from operations for reportable segments	$ 156,231	$ 142,517	$ 170,978	$ 145,625	$ 50,459	$ 117,331	$ 138,369	$ 140,637	$ 615,351	$ 446,796	$ 378,364
Interest expense									(43,049)	(50,992)	(39,875)
Debt retirement costs									(7,082)	0	0
Gain from sales of equity securities									16,429	0	0
Other income, (expense), net									3,520	5,628	4,471
Income before income taxes									$ 585,169	$ 401,432	$ 342,960