Supplemental Cash Flow Information (Details) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Supplemental Cash Flow Information
Cash paid for interest, net of amounts capitalized	$ 57,820	$ 49,541
Cash paid for income taxes, net of refunds	514	4,690
Supplemental schedule of non-cash investing and financing activities:
Accrued property, plant and equipment	58,429	56,578
Interest capitalized on construction in progress	199	2,705
Issuance of common units for vesting of share-based payment awards	$ 5,282	$ 7,030