Revenues - Contract Assets, Contract Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract assets, net	$ 62,907
Contract liabilities (deferred revenue)	212,668	$ 205,800
Revenue recognized in the period from:
Amounts included in contract liabilities at the beginning of the period	$ 86,655

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.

Reference 1: 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=121604090&loc=SL49130549-203045

Reference 2: 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=121556615&loc=SL49130531-203044

Reference 3: 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=121556615&loc=SL49130533-203044

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