Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (397,268)	$ 182,421	$ (499,938)	$ 89,957
Other comprehensive income (loss):
Foreign currency translation adjustment	368	(37)	40	278
Unrealized loss on available for sale securities	(7)	0	(7)	0
Amounts reclassified from accumulated other comprehensive income	0	0	0	(9,665)
Other comprehensive income (loss)	361	(37)	33	(9,387)
Comprehensive (loss) income	(396,907)	182,384	(499,905)	80,570
Less: comprehensive loss attributable to non-controlling interest	0	21	0	37
Comprehensive (loss) income attributable to The Medicines Company	$ (396,907)	$ 182,405	$ (499,905)	$ 80,607