CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Common Stock In Treasury	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2012	$ 459	$ (806,561)	$ 848,238	$ 975,232	$ (35)	$ 1,017,333
Balance (in shares) at Dec. 31, 2012	45,928	(18,575)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			21,252			21,252
Exercise of stock options	$ 12		47,281			47,293
Exercise of stock options (in shares)	1,139
Tax benefit from exercise of stock options and vesting of stock awards			2,297			2,297
Issuance of equity	$ 3		(596)			(593)
Issuance of equity (in shares)	284
Repurchase of stock		$ (60,153)				(60,153)
Repurchase of stock (in shares)		(1,160)
Adjustment to additional paid in capital due to reversal of tax contingency			3,853			3,853
Net income attributable to Magellan Health, Inc.				125,261		125,261
Other comprehensive loss-other					(58)	(58)
Balance at Dec. 31, 2013	$ 474	$ (866,714)	922,325	1,100,493	(93)	1,156,485
Balance (in shares) at Dec. 31, 2013	47,351	(19,735)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			40,584			40,584
Exercise of stock options	$ 12		52,982			52,994
Exercise of stock options (in shares)	1,191
Tax benefit from exercise of stock options and vesting of stock awards			2,980			2,980
Issuance of equity	$ 15		(369)			(354)
Issuance of equity (in shares)	1,543
Repurchase of stock		$ (198,249)				(198,249)
Repurchase of stock (in shares)		(3,415)
Adjustment to additional paid in capital due to reversal of tax contingency			2,591			2,591
Adjustment to non-controlling interest			(2,827)			(2,827)
Net income attributable to Magellan Health, Inc.				79,404		79,404
Other comprehensive loss-other					(50)	(50)
Balance at Dec. 31, 2014	$ 501	$ (1,064,963)	1,018,266	1,179,897	(143)	1,133,558
Balance (in shares) at Dec. 31, 2014	50,085	(23,150)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			50,384			50,384
Exercise of stock options	$ 11		54,079			54,090
Exercise of stock options (in shares)	1,140
Tax benefit from exercise of stock options and vesting of stock awards			3,530			3,530
Issuance of equity	$ 1		408			409
Issuance of equity (in shares)	115
Repurchase of stock		$ (204,428)				(204,428)
Repurchase of stock (in shares)		(3,498)
Adjustment to additional paid in capital due to reversal of tax contingency			32			32
Adjustment to non-controlling interest			(2,686)			(2,686)
Net income attributable to Magellan Health, Inc.				31,413		31,413
Other comprehensive loss-other					(119)	(119)
Balance at Dec. 31, 2015	$ 513	$ (1,269,391)	$ 1,124,013	$ 1,211,310	$ (262)	$ 1,066,183
Balance (in shares) at Dec. 31, 2015	51,340	(26,648)