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401(k) Plan (Details) - 401K Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Defined Contribution Plan, maximum annual contributions per employee, percent	60.00%
Defined Contribution Plan, matching contributions	$ 4.2	$ 5.1	$ 4.9
Prior to 2014 [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Defined Contribution Plan, employer matching contribution, percent of match	100.00%
Defined Contribution Plan, employer matching contribution, percent of employees' gross pay	6.00%
After 2014 [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Defined Contribution Plan, employer matching contribution, percent of match	150.00%
Defined Contribution Plan, employer matching contribution, percent of employees' gross pay	6.00%

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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.

+ References

No definition available.

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- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

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- Definition

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

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