Revenue Recognition, Future Undiscounted Fixed Payments from International Recurring Revenue Customers (Details) $ in Thousands	Jun. 30, 2021 USD ($)
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 69
International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	4,197
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 51
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 655
Expected timing of satisfaction period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 1,311
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 1,234
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 857
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 140
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | International [Member]
Remaining Performance Obligation [Abstract]
Future undiscounted fixed payments from international recurring revenue customers	$ 0
Expected timing of satisfaction period