|6 Months Ended|
Jun. 30, 2021
|Revenue from Contract with Customer [Abstract]|
|Changes in Deferred Revenue||The following table presents changes in the deferred revenue balance as of June 30:
Tabular disclosure of receivable, contract asset, and contract liability from contract with customer. Includes, but is not limited to, change in contract asset and contract liability.
Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef