Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balances at Dec. 31, 2010	$ 7,684	$ 691	$ 218,441	$ 2	$ (211,450)
Balance, Shares at Dec. 31, 2010		69,147,658
Common stock issued under Medivation Equity Incentive Plan, net of shares withheld for employee taxes, Amount	15,734	23	15,711
Common stock issued under Medivation Equity Incentive Plan, net of shares withheld for employee taxes, Shares		2,316,018
Stock-based compensation expense	13,774		13,774
Net proceeds from stockholder securities law settlement	2,959		2,959
Change in comprehensive income	11			11
Net loss	(38,841)				(38,841)
Balances at Dec. 31, 2011	1,321	714	250,885	13	(250,291)
Balance, Shares at Dec. 31, 2011		71,463,676
Common stock issued under Medivation Equity Incentive Plan, net of shares withheld for employee taxes, Amount	20,438	34	20,404
Common stock issued under Medivation Equity Incentive Plan, net of shares withheld for employee taxes, Shares		3,311,263
Stock-based compensation expense	23,678		23,678
Equity component of Convertible Notes, net of issuance costs	69,335		69,335
Stock appreciation rights-reclassification from current liabilities to stockholders' equity	110		110
Change in comprehensive income	20			20
Net loss	(41,257)				(41,257)
Balances at Dec. 31, 2012	73,645	748	364,412	33	(291,548)
Balance, Shares at Dec. 31, 2012	74,774,939	74,774,939
Common stock issued under Medivation Equity Incentive Plan, net of shares withheld for employee taxes, Amount	8,870	10	8,860
Common stock issued under Medivation Equity Incentive Plan, net of shares withheld for employee taxes, Shares		1,002,609
Common stock issued for warrant exercises, net of shares withheld for exercise price
Common stock issued for warrant exercises, net of shares withheld for exercise price, Shares		25,472
Stock-based compensation expense	37,078		37,078
Change in comprehensive income	(33)			(33)
Net loss	(42,613)				(42,613)
Balances at Dec. 31, 2013	$ 76,947	$ 758	$ 410,350		$ (334,161)
Balance, Shares at Dec. 31, 2013	75,803,020	75,803,020