Statement of Cash Flows (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Statement of Cash Flows [Abstract]
Increases to property, plant and equipment	$ (102,000)	$ (85,168)
Changes in related accounts payable and accrued liabilities	11,202	12,712
Capital expenditures	$ (90,798)	$ (72,456)