New Accounting Pronouncement and Changes in Accounting or Estimates Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2016
Item Effected [Line Items]
Proceeds and Excess Tax Benefit from Share-based Compensation		$ 7
Change In Accounting Estimate Financial Effect On Depreciation Expense for the Remainder of 2016	$ 29

The aggregate cash inflow comprised of the amount received from (a) employees to acquire the entity's shares under incentive awards, including stock option exercises and restricted stock arrangements, and (b) the excess tax benefit arising from such transactions.

No definition available.

Name:	us-gaap_ProceedsAndExcessTaxBenefitFromSharebasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration