Fair Value Measurements - Summary of Company's Fair Value Hierarchy for its Financial Assets and Liabilities (Parenthetical) (Detail) - Fair Value, Measurements, Recurring [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of liabilities	$ 4,196
Accrued Expenses and Other Current Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of liabilities	1,800
Non-current Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of liabilities	2,400
Corporate Obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Realized, loss	$ 200