CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Non-cash share-based compensation expense			$ 2,231	$ 7,116
Research and development expense
Non-cash share-based compensation expense	$ 3,125	$ 1,701	910	3,246
General and administrative expense
Non-cash share-based compensation expense	$ 3,491	$ 1,964	$ 1,321	$ 3,870