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

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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- Definition

The number of shares or units of entity securities issued in the transaction in which equity securities were issued to pay for goods or nonemployee services.

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- Definition

The amount by which stockholders' equity was increased by the transaction in which equity securities were issued to pay for goods or nonemployee services.

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Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) director $ / shares shares	Sep. 30, 2019 USD ($)
Stock-Based Compensation
Unrecognized compensation costs related to unvested share-based compensation arrangements	$ 14,400		$ 14,400
Weighted-average period for recognition of unrecognized stock-based compensation expense	2 years 3 months 18 days
Restricted Stock Units
Stock-Based Compensation
Stock-based compensation expense	$ 543
Awarded (in shares) \| shares			166,951
Weighted average granted date fair value (in dollars per share) \| $ / shares	$ 58.72		$ 74.91
Vesting period			3 years
Share-based Goods and Nonemployee Services Transaction, Quantity of Securities Issued \| shares	9,239
Weighted average exercise price (in dollars per share) \| $ / shares	$ 74.66
Employees
Stock-Based Compensation
Stock-based compensation expense	$ 4,000	$ 2,100	$ 9,500	$ 8,700
Employees \| Restricted Stock Units
Stock-Based Compensation
Vesting period			4 years
Director [Member] \| Restricted Stock Units
Stock-Based Compensation
Number Of Directors \| director			7
Share-based Goods and Nonemployee Services Transaction, Stockholders' Equity	$ 690