Long Term Incentive Plan 1 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Share Based Compensation Expense [Line Items]
Non Controlling Partners Interest In Share Based Compensation	$ 1,986	$ 994
Amount of related income tax benefit recognized in income	1,157	582
General and Administrative Expense [Member]
Share Based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	4,547	2,241
Operating Expense [Member]
Share Based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	559	323
Total Amount Charged To Income [Member]
Share Based Compensation Expense [Line Items]
Allocated Share-based Compensation Expense	$ 5,106	$ 2,564