Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Property, plant and equipment acquired with accrued liabilities	$ 3,870	$ 4,234	$ 13,590
Interest and Income Taxes (Paid) Refunded, Cash Flow Information [Abstract]
Interest (net of amounts capitalized)	(21,913)	(19,573)	(19,174)
Income taxes	0	0	219
Subsidiary of Common Parent [Member]
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Non-cash decrease to money pool note receivable, net	(28,501)	0	(8,000)
Parent [Member]
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Non-cash Dividend to Parent Company	$ 28,501	$ 0	$ 8,000