Acquisition of Biohaven Pharmaceuticals Inc (Details) $ in Thousands		3 Months Ended		12 Months Ended
	Dec. 31, 2016 USD ($)	Mar. 31, 2017 installment	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) item
Acquisition of Biohaven Pharmaceuticals, Inc.
Net loss attributable to non-controlling interests			$ 35
Biohaven Pharmaceuticals, Inc. | Majority Shareholder
Acquisition of Biohaven Pharmaceuticals, Inc.
Ownership interest acquired	100.00%			100.00%
Aggregate purchase consideration	$ 595
Number of founders | item				3
Equity share percentage owned by each founders	33.33%			33.33%
Number of installments in which notes are payable | installment		5
Number of interest only related party notes payable installments | installment		4
Interest rate of notes		4.50%
Carrying value of non-controlling interest derecognized	$ 86			$ 86
Reduction to additional paid-in capital				$ 509
Net loss attributable to non-controlling interests			$ 35