Redeemable Convertible Preferred Shares - Additional Information (Detail)			1 Months Ended		3 Months Ended	12 Months Ended
	Oct. 20, 2017	Jun. 30, 2017 $ / shares shares	Jul. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares shares
Class Of Stock [Line Items]
Conversion of bridge units in to preferred units					$ 8,500,000
Share conversion ratio		1
Common Stock [Member]
Class Of Stock [Line Items]
Reverse stock split ratio	0.164544
Reverse stock split	one-for-6.0774
Redeemable Convertible Preferred Shares [Member]
Class Of Stock [Line Items]
Redeemable convertible shares, par value | $ / shares		$ 0.001
Redeemable convertible shares, authorized | shares		43,297,267
Class C Preferred Units [Member]
Class Of Stock [Line Items]
Redeemable convertible shares issued and sold | shares				24,326,470		5,321,112
Redeemable convertible shares, par value | $ / shares				$ 1.7749	$ 1.7749
Proceeds from issuance of preferred units, net of issuance costs				$ 43,000,000
Payment of offering costs				$ 200,000
Preferred units discount percentage						10.00%
Conversion of bridge units in to preferred units						$ 8,500,000
Conversion price of redeemable preferred share | $ / shares						$ 1.60
Convertible debt fair value disclosures						$ 9,400,000
Liability fair value adjustment						8,500,000
Redeemable issuer option value						900,000
Gain on extinguishment						$ 0
Class C Preferred Units [Member] | Chief Financial Officer [Member]
Class Of Stock [Line Items]
Redeemable convertible shares issued and sold | shares			61,880
Redeemable convertible shares, par value | $ / shares			$ 1.7749
Proceeds from issuance of preferred units, net of issuance costs			$ 100,000