Recent Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Jul. 01, 2018	Jun. 30, 2018
Item Effected [Line Items]
Decrease to accumulated deficit			$ (175,801)		$ (207,115)
Increase in operating cash flow		$ 4,600
Adjustments for New Accounting Pronouncement [Member] | Other Expense [Member]
Item Effected [Line Items]
Reclassification of income from income (loss) from operations to other expense, net	$ 200	$ 400
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Item Effected [Line Items]
Decrease to accumulated deficit			$ (34,934)	$ 26,263