CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net (loss) income	$ (27,170)	$ 440
Adjustments for non-cash operating items:
Amortization of deferred revenue	(8,465)	(36,825)
Stock-based compensation	8,296	4,336
Amortization of debt discount and debt issuance costs	3,190	359
Depreciation on property and equipment	678	117
Accretion of discount on securities	(66)	(13)
Loss on disposal of equipment	35
Changes in operating assets and liabilities:
Receivables from collaboration partners	(4,684)	(1,970)
Prepaid expenses and other current assets	(1,548)	961
Other non-current assets	(173)	92
Accounts payable	1,019	3,409
Accrued expenses and other current liabilities	1,843	8,844
Interest payable	1,698	226
Other non-current liabilities	140	(237)
Net cash used in operating activities	(25,207)	(20,261)
Cash flows from investing activities:
Purchases of short-term investments	(59,969)	(149,950)
Maturities of short-term investments	125,000	25,000
Purchases of property and equipment	(1,424)	(1,255)
Change in restricted cash		(816)
Net cash provided by (used in) investing activities	63,607	(127,021)
Cash flows from financing activities:
Proceeds from issuance of Convertible Notes, net		250,987
Financing transaction costs		(488)
Proceeds from issuance of common stock under Medivation Equity Incentive Plan	1,823	6,794
Net cash provided by financing activities	1,823	257,293
Net increase in cash and cash equivalents	40,223	110,011
Cash and cash equivalents at beginning of period	71,301	70,136
Cash and cash equivalents at end of period	111,524	180,147
Non-cash investing activities:
Property and equipment expenditures incurred but not yet paid	$ 2,499	$ 1,876