Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2019 USD ($)
Significant Accounting Policies [Line Items]
Increase in total assets	$ 146,867,000	$ 134,269,000		$ 148,864,000
Increase in total liabilities	47,218,000	44,631,000		59,246,000
Impairment of long-lived assets	$ 0	0
Number of reportable segments | segment	1
Goodwill impairment loss	$ 0	0
Advertising expense	4,200,000	5,700,000	$ 5,300,000
Unrecognized tax benefits, income tax penalties and interest accrued	$ 0	$ 0
Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Increase in total assets				14,595,000
Increase in total liabilities				$ 14,615,000