XML 96 R78.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Supplemental Cash Flow Information - Narrative (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | ---
Supplemental Cash Flow Elements |  |  |
Municipal security activity in return for capital lease obigations, in aggregate | $ 13 | $ 13 | $ 12

X
- Definition Bonds or similar securities issued by state, city, or local governments or the agencies operated by state, city, or local governments which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. + References No definition available. + Details
Name: | us-gaap_MunicipalDebtSecuritiesAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_SupplementalCashFlowElementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration