Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (11,840)	$ (5,280)
Other comprehensive income (loss):
Foreign currency translation adjustments	259	(340)
Unrealized gain on marketable securities, net of tax	49	11
Other comprehensive income (loss)	308	(329)
Total comprehensive loss	(11,532)	(5,609)
Less: Net loss attributable to noncontrolling interest	(149)	(58)
Less: Other comprehensive income attributable to noncontrolling interest	30	10
Total comprehensive loss attributable to Demandware	$ (11,413)	$ (5,561)