Employee Stock Plans - Schedule of Stock-Based Compensation Awards (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Compensation And Retirement Disclosure [Abstract]
Stock options	$ 367	$ 479	$ 788	$ 998
Restricted stock units and awards	1,324	1,153	2,495	2,082
Performance share units	566	285	997	319
Total stock-based compensation expense	$ 2,257	$ 1,917	$ 4,280	$ 3,399

Performance share units.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

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-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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-Publisher FASB
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-SubTopic 10
-Section 50
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- Definition

Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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Amount of noncash expense for option under share-based payment arrangement.

+ References

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