Senior Notes And Other Debt (Schedule of Debt) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Subsidiary Debt
Debt Instrument [Line Items]
Face Value	$ 77,173,000	[1]
Carrying Value	77,173,000	[1]	57,795,000	[1]
Repayments in 2014	5,000,000
Repayments in 2015	40,000,000
Repayments in 2016	30,000,000
Repayments thereafter	2,000,000
Senior Notes and Other Debt
Debt Instrument [Line Items]
Face Value	1,703,676,000
Carrying Value	1,692,442,000		1,871,535,000
Senior Notes | Senior Notes due May 15, 2015
Debt Instrument [Line Items]
Rate	5.60%
Face Value	200,000,000
Carrying Value	199,744,000		199,559,000
Senior Notes | Senior Notes due August 15, 2019
Debt Instrument [Line Items]
Rate	6.15%
Face Value	150,000,000
Carrying Value	149,199,000		149,057,000
Senior Notes | Senior Notes due September 15, 2019
Debt Instrument [Line Items]
Rate	7.375%
Face Value	300,000,000
Carrying Value	298,546,000		298,292,000
Senior Notes | Senior Notes due September 15, 2020
Debt Instrument [Line Items]
Rate	5.375%
Face Value	300,000,000
Carrying Value	297,738,000		297,401,000
Senior Notes | Senior Notes due January 1, 2022
Debt Instrument [Line Items]
Rate	8.70%
Face Value	76,503,000
Carrying Value	76,004,000		75,962,000
Senior Notes | Senior Notes due March 15, 2022
Debt Instrument [Line Items]
Rate	4.625%
Face Value	350,000,000
Carrying Value	346,581,000		346,163,000
Senior Notes | Senior Notes due February 15, 2037
Debt Instrument [Line Items]
Rate	6.25%
Face Value	250,000,000
Carrying Value	$ 247,457,000		$ 247,347,000

[1] Subsidiary debt is due as follows: $5 million in 2014, $40 million in 2015, $30 million in 2016 and $2 million thereafter.