Income Taxes (Net Operating Loss Carryforwards and Tax Credit Carryforwards) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Internal Revenue Service (IRS) [Member]
Net Operating Loss Carryforwards	$ 858	$ 878
Tax Credit Carryforward	59	64
State and Local Jurisdiction [Member]
Net Operating Loss Carryforwards	2,249	2,272
Tax Credit Carryforward	$ 3	$ 3

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Carryforwards
-URI http://asc.fasb.org/extlink&oid=6506874

Name:	us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant