General (Details 9) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014
General
Projected fees Under Affordable Care Act					$ 26.4
Fees Under Affordable Care Act Expense	$ 6.3	$ 5.6	$ 13.2	$ 10.7		$ 21.4
Amount of Revenues Associated with Accrual for Reimbursement of Economic Impact of Affordable Care Act Fees from its Customers	$ 10.7	$ 10.9	$ 22.4	$ 14.1

The amount of revenues recorded associated with the accrual for the reimbursement of the economic impact of the ACA fees from its customers.

No definition available.

Name:	mgln_AmountOfRevenuesAssociatedWithAccrualForReimbursementOfEconomicImpactOfAffordableCareActFeesFromItsCustomers
Namespace Prefix:	mgln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration