Business Acquisitions Contract Price and Fair Value of Consideration Transferred (Details) (Alaska Energy Resources Company [Member], USD $) In Thousands, unless otherwise specified	0 Months Ended	9 Months Ended
	Jul. 01, 2014	Sep. 30, 2014	Jul. 01, 2014
Alaska Energy Resources Company [Member]
Business Acquisition [Line Items]
Merger Consideration - Total			$ 170,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents			19,704
Business Acquisition Recognized Identifiable Assets Acquired and Liabilities Assumed Current and Long-Term Debt			(38,832)
Business Acquisition Contract Price Closing Adjustments			(104)
Business Acquisition Adjusted Contract Price			150,768
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	150,075
Payments to Acquire Businesses, Gross		4,697
Business Combination, Consideration Transferred	$ 154,772