XML 131 R100.htm IDEA: XBRL DOCUMENT
v3.20.4

Pension Plans and Other Postretirement Benefit Plans - Employer Matching Contributions (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
General Discussion Of Pension And Other Postretirement Benefits [Abstract] |  |  |
Employer 401(k) matching contributions | $ 11,742 | $ 10,412 | $ 10,243

X
- 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 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_GeneralDiscussionOfPensionAndOtherPostretirementBenefitsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration