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.

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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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Impairment Losses - Goodwill Balances (Details) - USD ($)	3 Months Ended		12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2017	Dec. 31, 2016
Goodwill
Historical goodwill					$ 678,000,000
Accumulated impairment losses				$ (248,000,000)	(58,000,000)
Goodwill	$ 430,000,000		$ 620,000,000	430,000,000	620,000,000
Goodwill
Impairment loss	(129,000,000)	$ (61,000,000)	0
Ending balance	430,000,000		620,000,000
Accumulated impairment losses				248,000,000	58,000,000
Health Plans
Goodwill
Historical goodwill					445,000,000
Accumulated impairment losses				(58,000,000)	(58,000,000)
Goodwill	387,000,000		387,000,000	387,000,000	387,000,000
Goodwill
Impairment loss	0	0
Ending balance	387,000,000		387,000,000
Accumulated impairment losses				58,000,000	58,000,000
Molina Medicaid Solutions
Goodwill
Historical goodwill					71,000,000
Accumulated impairment losses				(28,000,000)	0
Goodwill	43,000,000		71,000,000	43,000,000	71,000,000
Goodwill
Impairment loss	(28,000,000)	0
Ending balance	43,000,000		71,000,000
Accumulated impairment losses				28,000,000	0
Other segment
Goodwill
Historical goodwill					162,000,000
Accumulated impairment losses				(162,000,000)	0
Goodwill	0		162,000,000	0	162,000,000
Goodwill
Impairment loss		$ (61,000,000)
Ending balance	$ 0		$ 162,000,000
Accumulated impairment losses				$ 162,000,000	$ 0