Contingencies (NPM Adjustment Calculation Narrative) (Details) - Jun. 30, 2015 - Segments [Domain] - Loss Contingency, Nature [Domain] - Entity [Domain] $ in Millions	USD ($) state
Loss Contingencies [Line Items]
Partial Liability Reduction Percentage for 2003 N P M Adjustment for States that Are Party to Agreement re: Arbitration	20.00%
Challenges To MSA Found In Favor Of Defendants	16
States Not Diligently Enforcing Escrow Statutes | state	6
Year NPM Adjustment Calculated 2013 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	$ 219
Year NPM Adjustment Calculated 2012 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	211
Year Npm Adjustment Calculated 2011 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	166
Year Npm Adjustment Calculated 2010 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	218
Year NPM Adjustment Calculated 2009 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	211
Year Npm Adjustment Calculated 2008 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	250
Year Npm Adjustment Calculated 2007 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	185
Year Npm Adjustment Calculated 2006 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	154
Year Npm Adjustment Calculated 2005 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	181
Year Npm Adjustment Calculated 2004 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	388
Year NPM Adjustment Calculated 2014 [Member]
Loss Contingencies [Line Items]
Affiliates Possible Excess MSA Payments	$ 247
2004-214 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Non-signatory States | state	17