Segment Information - Schedule of Operating Segment Information (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenue	[1]	$ 4,546	$ 3,611	$ 13,248	$ 10,307
Gross margin		457	374	1,331	1,114
Total Assets		7,570		7,570		$ 6,576
Health Plans
Segment Reporting Information [Line Items]
Revenue	[1]	4,412	3,562	12,835	10,155
Gross margin		443	361	1,285	1,071
Total Assets		5,891		5,891		4,707
Medicaid Solutions Segment
Segment Reporting Information [Line Items]
Revenue	[1]	48	47	146	146
Gross margin		6	13	17	43
Total Assets		267		267		213
Other
Segment Reporting Information [Line Items]
Revenue	[1]	86	2	267	6
Gross margin		8	$ 0	29	$ 0
Total Assets		$ 1,412		$ 1,412		$ 1,656

[1] Total revenue consists primarily of premium revenue for the Health Plans segment, and service revenue for the Molina Medicaid Solutions and Other segments.