Stock Plans and Stock-Based Compensation - Restricted Stock Units - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 11,278	$ 8,282	$ 21,588	$ 16,131
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation, number of stock unit grants in period			127,037
Stock-based compensation expense	4,800	$ 4,600	$ 9,300	$ 8,400
Number of stock units vested			66,113
Weighted-average grant date fair values of units granted			$ 109.31	$ 64.12
Fair values of stock units			$ 4,000	$ 3,600
Unrecognized compensation expense	$ 37,900		$ 37,900
Weighted-average amortization period			2 years 5 months 19 days

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

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