Revenue Recognition (Contract with Customer, Asset and Liability) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Accounts receivable (including long-term, included in Other assets)	$ 1,039,981	$ 1,081,070
Contract assets, short-term (included in Other current assets)	7,837	9,830
Contract assets, long-term (included in Other assets)	942	942
Contract liabilities (Deferred revenue)	$ 81,848	$ 71,048

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123360276&loc=SL49130533-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=123360276&loc=SL49130531-203044

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant