Basis of Presentation and Summary of Significant Accounting Polices - Description of Business (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) segment	Jun. 30, 2021 $ / shares	Jan. 25, 2021 $ / shares	Dec. 15, 2020 $ / shares
General And Basis Of Presentation1 [Line Items]
Number of operating segments | segment	3
Professional fees | $	$ 8.8
Catalyst Holdings
General And Basis Of Presentation1 [Line Items]
Amount to be paid per share (in dollars per share)				$ 35.00
Definitive agreement, price per share (in dollars per share)				$ 35.00
NCR | Forecast | Subsequent Event
General And Basis Of Presentation1 [Line Items]
Amount to be paid per share (in dollars per share)		$ 39.00	$ 39.00
Cardtronics Mexico
General And Basis Of Presentation1 [Line Items]
Ownership in subsidiary	95.70%