Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (30,175)	$ (86,271)	$ (530,113)	$ 3,686
Other comprehensive income (loss):
Foreign currency translation adjustment	487	(70)	527	208
Unrealized gain on available for sale securities	10	0	3	0
Amounts reclassified from accumulated other comprehensive income	0	0	0	(9,665)
Other comprehensive income (loss)	497	(70)	530	(9,457)
Comprehensive loss	(29,678)	(86,341)	(529,583)	(5,771)
Less: comprehensive loss attributable to non-controlling interest	0	13	0	50
Comprehensive loss attributable to The Medicines Company	$ (29,678)	$ (86,328)	$ (529,583)	$ (5,721)