Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets:
Options and deferred compensation	$ 7,741	$ 10,236
Accrued expenses	4,519	3,841
Foreign tax credits	31,162	40,439
Tax attribute carryforwards	10,948	20,209
Derivatives	10,661	6,808
Intangibles	0	508
Other, net	4,126	1,789
Deferred tax assets	69,157	83,830
Valuation allowance	(11,253)	(17,283)
Net deferred tax assets	57,904	66,547
Deferred tax liabilities:
Property	(193,923)	(184,969)
Derferred Tax Liability, Intangibles	(3,865)	0
Foreign currency translation	(8,672)	(5,000)
Deferred tax liabilities	206,460	189,969
Net deferred tax liability	(148,556)	(123,422)
Benefit of reduced statutory foreign tax rate	1,600
Net current and non-current components of deferred taxes:
Net current deferred tax asset	8,184	10,345
Net non-current deferred tax liability	(156,740)	(133,767)
Net deferred tax liability	$ (148,556)	$ (123,422)