Employee Benefit Plans (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer matching contribution, percentage on first 3%	100.00%
Employer matching contribution, percentage on next 2%	50.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 100% under the Deferred Plan	3.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 50% under the Deferred Plan	2.00%
Total liabilities under Deferred Plan	$ 15,296	$ 12,811
Fair value of investments in rabbi trust	$ 15,296	$ 12,811
Employee Stock Purchase Plan (ESPP) [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Period of service before an employee is eligible for contribution	1 year
ESPP employee contribution, percentage	15.00%
Purchase price percentage of fair market value of stock on last trading date of monthly exercise period	95.00%
Common stock authorized and reserved for ESPP	250
Common stock authorized for issuance but not yet issued for ESPP	245
Shares issued under ESPP	1	1	1
401(k) Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer matching contribution, percentage on first 3%	100.00%
Employer matching contribution, percentage on next 2%	50.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 100%	3.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 50%	2.00%
Period of service before an employee is eligible for contribution	1 year
Company matching contributions	$ 8,490	$ 6,968	$ 6,090

Common stock reserved for issuance under the Company's ESPP.

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- Definition

Common stock authorized for issuance but not yet issued for ESPP

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- Definition

Deferred Compensation Arrangement With Individual Employer Contribution Percentage On First 3 Percent

+ References

No definition available.

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- Definition

Deferred Compensation Arrangement With Individual Employer Contribution Percentage On Next 2 Percent

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- Definition

Deferred compensation arrangement with individual, employer matching contribution of 100 percent

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- Definition

Deferred compensation arrangement with individual, employer matching contribution of 50 percent

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- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay, at Which Employer Matches 100 Percent

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No definition available.

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- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay, at Which Employer Matches 50 Percent

+ References

No definition available.

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- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Match On First 3%

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- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Match On Next 2 Percent

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No definition available.

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- Definition

The maximum percent an employee may contribute after one year of service with the Company.

+ References

No definition available.

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- Definition

Eligibility period to contribute to the ESPP.

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No definition available.

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- Definition

Eligibility period to receive matching contributions

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- Definition

Purchase price percentage of fair market value of stock on last trading date of monthly exercise period.

+ References

No definition available.

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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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No definition available.

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- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

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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
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- Definition

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

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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