Schedule I - Condensed Financial Information, Short-term and Long-term Debt (Details) $ in Millions	Dec. 31, 2018 USD ($)
Maturities Of Debt Excluding Capital Leases [Abstract]
Scheduled maturities, long-term debt, 2019	$ 1,337
Scheduled maturities, long-term debt, 2020	4,700
Scheduled maturities, long-term debt, 2021	7,378
Scheduled maturities, long-term debt, 2022	2,250
Scheduled maturities, long-term debt, 2023	4,917
Scheduled maturities, long-term debt, after 2023	20,582
Cigna [Member]
Maturities Of Debt Excluding Capital Leases [Abstract]
Scheduled maturities, long-term debt, 2019	0
Scheduled maturities, long-term debt, 2020	2,750
Scheduled maturities, long-term debt, 2021	5,250
Scheduled maturities, long-term debt, 2022	0
Scheduled maturities, long-term debt, 2023	3,800
Scheduled maturities, long-term debt, after 2023	$ 11,200

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04.(a))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

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