Income Taxes (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Contingency [Line Items]
Deferred Tax Assets, Net, Current	$ 20		$ 50
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Adjustment of deferred tax balances	$ 17	$ 15

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, netted by jurisdiction and classified as current.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31917-109318

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=37586315&loc=d3e31931-109318

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

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