Acquisitions, Dispositions and Exchanges Acquisitions, Dispositions and Exchanges (Pro Forma Financials) (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Acqusitions, Dispositions and Exchanges [Abstract]
Pro Forma Operating revenues	$ 3,595,121	$ 3,547,856
Pro Forma Net income (loss)	$ 1,292,421	$ 227,556

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

Name:	us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration