Statement of Cash Flows (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Statement of Cash Flows [Abstract]
Increases to property, plant and equipment	$ (54,479)	$ (36,850)
Changes in related accounts payable and accrued liabilities	7,332	605
Capital expenditures	$ (47,147)	$ (36,245)