Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Goodwill and Intangible Assets, Net - Balances of Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Historical goodwill		$ 678,000,000
Accumulated impairment losses	$ (492,000,000)	(58,000,000)
Changes in the carrying amount of goodwill
Beginning balance	620,000,000
Impairment losses, year ended December 31, 2017	(434,000,000)	0
Ending balance	186,000,000	620,000,000
Health Plans
Goodwill [Line Items]
Historical goodwill		445,000,000
Accumulated impairment losses	(302,000,000)	(58,000,000)
Changes in the carrying amount of goodwill
Beginning balance	387,000,000
Impairment losses, year ended December 31, 2017	(244,000,000)
Ending balance	143,000,000	387,000,000
Molina Medicaid Solutions
Goodwill [Line Items]
Historical goodwill		71,000,000
Accumulated impairment losses	(28,000,000)	0
Changes in the carrying amount of goodwill
Beginning balance	71,000,000
Impairment losses, year ended December 31, 2017	(28,000,000)
Ending balance	43,000,000	71,000,000
Other
Goodwill [Line Items]
Historical goodwill		162,000,000
Accumulated impairment losses	(162,000,000)	0
Changes in the carrying amount of goodwill
Beginning balance	162,000,000
Impairment losses, year ended December 31, 2017	(162,000,000)
Ending balance	$ 0	$ 162,000,000