Stock Plans and Share-Based Compensation - Shares Issued Under Employee Stock Purchase Plan (Details) - ESPP - Employee Stock Purchase Plan - $ / shares shares in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)	334	360	730	726
Weighted average purchase price per share (in dollars per share)	$ 24.93	$ 19.76	$ 21.90	$ 20.13

Number of shares issued under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration