Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Valuation allowance	$ (95,558,000)	$ (5,838,000)
Excess tax benefits from the exercises of employee stock options	6,900,000	3,000,000
Mexican tax credits	2,900,000
Unrecognized tax benefit that would impact effect tax rate	30,600,000	34,500,000
Losses related to employee stock options	300,000,000
Impact of uncertain tax positions minimum	0
Impact of uncertain tax positions maximum	1,300,000
Reduction as a result of the lapse of statute limitations	4,926,000	467,000	53,000
Penalties and tax-related interest expense (income)	(2,900,000)	9,100,000	2,300,000
Total unrecognized tax benefits included in other long-term liabilities	34,337,000	38,886,000	79,012,000	87,975,000
The total amount of accrued income tax related interest and penalties included in other long-term liabilities	28,700,000	31,500,000
Deferred tax benefit due to the REIT conversion		121,000,000
Income tax benefit	107,304,000	125,080,000	182,489,000
Deferred Tax Liability Related To Undistributed Foreign Earnings	101,000,000
Federal [Member]
Future federal and state net operating loss carryforwards	922,893,000
Long-Term Liabilities [Member]
Total unrecognized tax benefits included in other long-term liabilities	$ 34,300,000	$ 36,600,000