Overview and Basis of Presentation - Summary of Cash and Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 103,209	$ 103,077	$ 129,050	$ 127,246
Cash and Cash Equivalents and Restricted Cash	104,465	104,396	130,683	129,185
Other Current Assets [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in "Other current assets"	290	355	318	568
Deferred Charges and Other Assets [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in "Deferred charges and other assets"	$ 966	$ 964	$ 1,315	$ 1,371