Supplemental Condensed Consolidating Financial Information - Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 2,979	$ 2,819	$ 2,345	$ 2,329
Investments	2,192	1,758
Restricted investments	325	0
Receivables	1,006	974
Income taxes refundable	68	39
Due from (to) affiliates	0	0
Prepaid expenses and other current assets	159	131
Derivative asset	440	267
Total current assets	7,169	5,988
Property, equipment, and capitalized software, net	449	454
Deferred contract costs	93	86
Goodwill and intangible assets, net	671	760
Restricted investments	118	110
Investment in subsidiaries, net	0	0
Deferred income taxes	36	10
Other assets	47	41
Total assets	8,583	7,449
Current liabilities:
Medical claims and benefits payable	2,077	1,929	1,766	1,685
Amounts due government agencies	1,844	1,202
Accounts payable and accrued liabilities	375	385
Deferred revenue	284	315
Current portion of long-term debt	773	472
Derivative liability	440	267
Total current liabilities	5,793	4,570
Long-term debt	1,215	1,173
Deferred income taxes	0	15
Other long-term liabilities	54	42
Total liabilities	7,062	5,800
Total stockholders' equity	1,521	1,649
Total liabilities and stockholders' equity	8,583	7,449
Eliminations
Current assets:
Cash and cash equivalents	0	0	0	0
Investments	0	0
Restricted investments	0
Receivables	0	0
Income taxes refundable	0	0
Due from (to) affiliates	0	0
Prepaid expenses and other current assets	0	0
Derivative asset	0	0
Total current assets	0	0
Property, equipment, and capitalized software, net	0	0
Deferred contract costs	0	0
Goodwill and intangible assets, net	0	0
Restricted investments	0	0
Investment in subsidiaries, net	(2,778)	(2,855)
Deferred income taxes	(10)	0
Other assets	(16)	(16)
Total assets	(2,804)	(2,871)
Current liabilities:
Medical claims and benefits payable	0	0
Amounts due government agencies	0	0
Accounts payable and accrued liabilities	0	0
Deferred revenue	0	0
Current portion of long-term debt	0	0
Derivative liability	0	0
Total current liabilities	0	0
Long-term debt	(16)	(16)
Deferred income taxes	(10)	0
Other long-term liabilities	0	0
Total liabilities	(26)	(16)
Total stockholders' equity	(2,778)	(2,855)
Total liabilities and stockholders' equity	(2,804)	(2,871)
Parent Guarantor \| Reportable Legal Entities
Current assets:
Cash and cash equivalents	109	86	214	360
Investments	56	178
Restricted investments	325
Receivables	2	2
Income taxes refundable	7	17
Due from (to) affiliates	137	104
Prepaid expenses and other current assets	70	58
Derivative asset	440	267
Total current assets	1,146	712
Property, equipment, and capitalized software, net	297	301
Deferred contract costs	0	0
Goodwill and intangible assets, net	56	58
Restricted investments	0	0
Investment in subsidiaries, net	2,597	2,609
Deferred income taxes	10	10
Other assets	55	48
Total assets	4,161	3,738
Current liabilities:
Medical claims and benefits payable	0	1
Amounts due government agencies	0	0
Accounts payable and accrued liabilities	170	146
Deferred revenue	0	0
Current portion of long-term debt	773	472
Derivative liability	440	267
Total current liabilities	1,383	886
Long-term debt	1,215	1,173
Deferred income taxes	10	11
Other long-term liabilities	32	19
Total liabilities	2,640	2,089
Total stockholders' equity	1,521	1,649
Total liabilities and stockholders' equity	4,161	3,738
Other Guarantors \| Reportable Legal Entities
Current assets:
Cash and cash equivalents	32	6	5	13
Investments	0	0
Restricted investments	0
Receivables	30	34
Income taxes refundable	1	4
Due from (to) affiliates	(6)	(5)
Prepaid expenses and other current assets	21	30
Derivative asset	0	0
Total current assets	78	69
Property, equipment, and capitalized software, net	47	46
Deferred contract costs	93	86
Goodwill and intangible assets, net	72	73
Restricted investments	0	0
Investment in subsidiaries, net	181	246
Deferred income taxes	(43)	0
Other assets	2	3
Total assets	430	523
Current liabilities:
Medical claims and benefits payable	0	0
Amounts due government agencies	0	0
Accounts payable and accrued liabilities	35	34
Deferred revenue	49	40
Current portion of long-term debt	0	0
Derivative liability	0	0
Total current liabilities	84	74
Long-term debt	0	0
Deferred income taxes	0	39
Other long-term liabilities	1	1
Total liabilities	85	114
Total stockholders' equity	345	409
Total liabilities and stockholders' equity	430	523
Non-Guarantors \| Reportable Legal Entities
Current assets:
Cash and cash equivalents	2,838	2,727	$ 2,126	$ 1,956
Investments	2,136	1,580
Restricted investments	0
Receivables	974	938
Income taxes refundable	60	18
Due from (to) affiliates	(131)	(99)
Prepaid expenses and other current assets	68	43
Derivative asset	0	0
Total current assets	5,945	5,207
Property, equipment, and capitalized software, net	105	107
Deferred contract costs	0	0
Goodwill and intangible assets, net	543	629
Restricted investments	118	110
Investment in subsidiaries, net	0	0
Deferred income taxes	79	0
Other assets	6	6
Total assets	6,796	6,059
Current liabilities:
Medical claims and benefits payable	2,077	1,928
Amounts due government agencies	1,844	1,202
Accounts payable and accrued liabilities	170	205
Deferred revenue	235	275
Current portion of long-term debt	0	0
Derivative liability	0	0
Total current liabilities	4,326	3,610
Long-term debt	16	16
Deferred income taxes	0	(35)
Other long-term liabilities	21	22
Total liabilities	4,363	3,613
Total stockholders' equity	2,433	2,446
Total liabilities and stockholders' equity	$ 6,796	$ 6,059

Medical Premium Liability Due to Agency

No definition available.

Name:	moh_MedicalPremiumLiabilityDueToAgency
Namespace Prefix:	moh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.