v3.8.0.1

Medical Claims Liability - Incurred Claims and Allocated Claims Adjustment Expenses (Details) - Health insurance product line claim in Millions, $ in Millions | Dec. 31, 2017 USD ($) claim | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
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Claims Development [Line Items] |  |  |
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net | $ 102,831 |  |
Short-duration insurance contracts, accident year 2015 |  |  |
Claims Development [Line Items] |  |  |
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net | 30,310 | $ 30,325 | $ 30,619
Short-duration insurance contracts, expected development on reported claims | $ 0 |  |
Short-duration Insurance contracts, number of reported claims | claim | 156.7 |  |
Short-duration insurance contracts, accident year 2016 |  |  |
Claims Development [Line Items] |  |  |
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net | $ 34,296 | $ 34,655 |
Short-duration insurance contracts, expected development on reported claims | $ 48 |  |
Short-duration Insurance contracts, number of reported claims | claim | 179.1 |  |
Short-duration insurance contracts, accident year 2017 |  |  |
Claims Development [Line Items] |  |  |
Short-duration insurance contracts, incurred claims and allocated claim adjustment expense, net | $ 38,225 |  |
Short-duration insurance contracts, expected development on reported claims | $ 3,330 |  |
Short-duration Insurance contracts, number of reported claims | claim | 192.0 |  |

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- Definition Short-duration Insurance Contracts, Incurred but Not Reported Liabilities and Expected Development on Reported Claims + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Undiscounted amount, after reinsurance, of incurred claims and allocated claim adjustment expense used in claims development for short-duration insurance contracts. Excludes unallocated claim adjustment expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671311-158438 + Details
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- Definition Number of reported claims for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671317-158438 + Details
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