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, 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 income (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 income (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)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			37,422			37,422
Exercise of stock options	$ 6		24,542			24,548
Exercise of stock options (in shares)	494
Adjustment due to adoption of ASU 2016-09				99		99
Tax benefit from exercise of stock options and vesting of stock awards						800
Issuance of equity	$ 1		1,229			1,230
Issuance of equity (in shares)	159
Repurchase of stock		$ (106,806)				(106,806)
Repurchase of stock (in shares)		(1,828)
Adjustment to non-controlling interest			(923)			(923)
Net income attributable to Magellan Health, Inc.				77,879		77,879
Other comprehensive income (loss)-other					87	87
Balance at Dec. 31, 2016	$ 520	$ (1,376,197)	$ 1,186,283	$ 1,289,288	$ (175)	$ 1,099,719
Balance (in shares) at Dec. 31, 2016	51,993	(28,476)