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Revenue from Contracts with Customers - Contract Assets Rollforward (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2020 | Mar. 31, 2019
Capitalized Cost To Fulfill Customer Contracts |  |
Change in Capitalized Contract Costs |  |
Balance at beginning of period | $ 335 | $ 329
Additions | 318 | 346
Amortization | (416) | (439)
Impairment | 0 | 0
Foreign currency translation and other | (8) | 0
Balance at end of period | 229 | 236
Capitalized Cost To Obtain Customer Contracts |  |
Change in Capitalized Contract Costs |  |
Balance at beginning of period | 171 | 156
Additions | 12 | 9
Amortization | (12) | (11)
Impairment | 0 | 0
Foreign currency translation and other | (4) | 1
Balance at end of period | $ 167 | $ 155

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- Definition Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054 + Details
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- Definition Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054 + Details
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- Definition Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer. + References 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 + Details
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