Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Asset reserves and liabilities not yet deductible for tax	$ 14,350	$ 17,386
Net current deferred tax assets	14,350	17,386
Current deferred tax liabilities, Other	(2,582)	(3,254)
Net total current deferred tax assets	11,768	14,132
Asset reserves and liabilities not yet deductible for tax	21,145	19,906
Tax over book basis of certain assets	17,347	19,376
Net operating loss and tax credit carryforwards	9,095	11,432
Noncurrent deferred tax assets, Other	874	2,178
Total noncurrent deferred tax assets	48,461	52,892
Less valuation allowance	(2,862)	(3,859)
Net noncurrent deferred tax assets	45,599	49,033
Book over tax basis of certain assets	(182,084)	(167,271)
Deferred tax liabilities, other	(18)	(7)
Total noncurrent deferred tax liabilities	(182,102)	(167,278)
Net total noncurrent deferred tax liabilities	$ (136,503)	$ (118,245)