Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Supplemental Cash Flow Information [Abstract]
Cash paid during the year for interest, net of amounts capitalized and deferred	$ 46,165	$ 49,219
Balance in property, plant and equipment, net funded with accounts payable and accrued liabilities	$ 383,722	$ 286,388