Income Taxes (Summary Of Tax Loss And Tax Credit Carryforwards) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Tax Credit Carryforward [Line Items]
Deferred tax asset on tax carryforwards	$ 93,337	$ 78,289
Valuation Allowance, Amount	(58,062)
Net deferred tax asset on tax carryforwards	35,275
U.S. Federal Tax Credits [Member]
Tax Credit Carryforward [Line Items]
2012-201	105
After 2016	34,430
Total tax carryforwards	34,535
Deferred tax asset on tax carryforwards	34,535
Valuation Allowance, Amount	(105)
Net deferred tax asset on tax carryforwards	34,430
U.S Federal Tax Losses [Member]
Tax Credit Carryforward [Line Items]
After 2016	505
Total tax carryforwards	505
Deferred tax asset on tax carryforwards	177
Net deferred tax asset on tax carryforwards	177
U.S. State Tax Credits [Member]
Tax Credit Carryforward [Line Items]
2012-201	1,624
After 2016	3,253
Indefinite	13,969
Total tax carryforwards	18,846
Deferred tax asset on tax carryforwards	12,250
Valuation Allowance, Amount	(11,587)
Net deferred tax asset on tax carryforwards	663
U.S. State Tax Losses [Member]
Tax Credit Carryforward [Line Items]
2012-201	136,179
After 2016	342,590
Total tax carryforwards	478,769
Deferred tax asset on tax carryforwards	27,880
Valuation Allowance, Amount	(27,880)
Non-U.S. Tax Losses [Member]
Tax Credit Carryforward [Line Items]
2012-201	10,470
After 2016	24,963
Indefinite	29,748
Total tax carryforwards	65,181
Deferred tax asset on tax carryforwards	18,495
Valuation Allowance, Amount	(18,490)
Net deferred tax asset on tax carryforwards	$ 5