Equity Award Plan Activities - Narrative (Details) - 2014 Employee Stock Purchase Plan - ESPP - $ / shares		3 Months Ended
Jan. 01, 2019	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of additional shares authorized for issuance (in shares)	756,679
Percent of shares outstanding to increase number of shares available for grant and issuance	1.00%
Maximum increase of number of shares available for issuance (in shares)	2,500,000
Common stock reserved for issuance (in shares)		3,244,374
Shares issued during period (in shares)		45,743
Weighted-average grant-date fair value of options granted (in dollars per share)		$ 190.31

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Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Additional Shares to be Authorized

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Aggregate number of common shares reserved for future issuance.

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Number of additional shares authorized for issuance under an established share-based compensation plan.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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