Quarterly Financial Data (Unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 103,601	$ 97,295	$ 96,216	$ 96,829	$ 93,013	$ 91,951	$ 92,207	$ 89,207	$ 393,941	$ 366,378	$ 336,123
Gross profit	45,325	40,607	41,166	41,190	37,864	39,181	38,423	36,517	168,288	151,985	131,471
Loss from operations	(1,831)	(8,283)	(2,056)	(1,681)	(2,154)	24	(1,180)	(975)	(13,851)	(4,285)	(14,629)
Net loss	(2,311)	(8,894)	(2,579)	(1,541)	(2,419)	(890)	(2,225)	(1,783)	(15,325)	(7,317)	(16,260)
Net loss attributable to stockholders of NxStage Medical, Inc.	(2,269)	(8,445)	(2,089)	(1,189)	(1,597)	(166)	(1,732)	(1,276)	(13,992)	(4,771)	(15,342)
Net loss attributable to common stockholders	$ (2,269)	$ (8,926)	$ (2,089)	$ (1,189)	$ (1,597)	$ (166)	$ (1,732)	$ (1,276)	$ (14,473)	$ (4,771)	$ (15,342)
Net loss per share, basic and diluted (in dollars per share)	$ (0.03)	$ (0.14)	$ (0.03)	$ (0.02)	$ (0.02)	$ 0.00	$ (0.03)	$ (0.02)	$ (0.22)	$ (0.07)	$ (0.24)