Description of Business and Summary of Significant Accounting Policies - Summary of Fair Value Hierarchy for Financial Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 30,307
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	30,307	$ 76,600
Fair Value, Measurements, Recurring [Member] | Money Market Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,478	10,988
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	13,382	36,478
Fair Value, Measurements, Recurring [Member] | Pre-refunded Municipals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	1,063	26,697
Fair Value, Measurements, Recurring [Member] | Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	9,585	2,437
Fair Value, Measurements, Recurring [Member] | Federal Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	3,799
Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,478	10,988
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,478	10,988
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Pre-refunded Municipals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Federal Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	27,829	65,612
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	13,382	36,478
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Pre-refunded Municipals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	1,063	26,697
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	9,585	2,437
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Federal Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	3,799
Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Pre-refunded Municipals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Corporate Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	$ 0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Federal Agency Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 0