Comprehensive Loss (Detail) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Equity [Abstract]
Other Comprehensive Income (Loss), Net of Tax	$ 0	$ 0	$ 0	$ 0

Amount after tax and reclassification adjustments of other comprehensive income (loss).

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+ Details