Relationship with IBM and Related Party Transactions - Support Agreement (Details) $ in Millions	Mar. 31, 2020 USD ($)
IBM Credit LLC | IBM
Related party transactions
Minimum beneficial ownership of equity voting interest (as a percent)	51.00%
IBM | Support Agreement
Related party transactions
Minimum consolidated tangible net worth to be supported by parent company	$ 50
Maximum debt to equity ratio to be supported by parent company	11