Revenues and Contract Costs - Schedule of Cost Incurred to Obtain or Fulfill Contracts with Customers (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Capitalized Contract Cost [Line Items]
Deferred contract costs	$ 4,489	$ 3,895
Prepaid expenses and other
Capitalized Contract Cost [Line Items]
Deferred contract costs	2,578	2,083
Other Assets
Capitalized Contract Cost [Line Items]
Deferred contract costs	$ 1,911	$ 1,812

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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