Cash and Cash Equivalents and Investments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 162,530	$ 202,422	$ 162,530	$ 202,422	$ 151,359
Cash	150,300		150,300		139,300
Short-term investment	21,042		21,042		0
Loss on short-term investments	3,474	0	33,463	0
Restricted Cash
Restricted cash	5,433	$ 5,033	5,433	$ 5,033	5,541
Restricted cash, letter of credit - foreign taxes	4,200		4,200		4,200
Restricted cash, letter of credit - lease agreement					1,000
Restricted cash, guaranteed investment certificate for collateralizing an available credit facility					200
Restricted cash, foreign tender requirements	200		200		300
Melinta
Cash and Cash Equivalents [Line Items]
Short-term investment	21,000		21,000
Money market funds
Cash and Cash Equivalents [Line Items]
Cash equivalents	$ 12,200		$ 12,200		$ 12,100