Annual report pursuant to Section 13 and 15(d)

COMMITMENTS AND CONTINGENCIES - Narrative (Details)

v3.20.4
COMMITMENTS AND CONTINGENCIES - Narrative (Details)
 12 Months Ended
Jul. 22, 2019
USD ($)
Dec. 31, 2020
USD ($)
claim
plaintiff
lawsuit
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Commitments and Contingencies Disclosure [Line Items]        
Cash paid for data processing, outsourcing services and other agreements   $ 50,000,000 $ 52,000,000 $ 49,000,000
Change in control event, voting stock acquired (or more)   20.00%    
Percent of common stock received upon merger   66.67%    
Conditional payment for unrecognized severance benefit for key executives   $ 32,400,000    
Relative total shareholder return, period   3 years    
Conditional payout percentage of target award   100.00%    
Accrual related to indemnifications   $ 0 0  
Google Agreement        
Commitments and Contingencies Disclosure [Line Items]        
Expected future year's minimum contractual obligation   120,000,000    
Expected future year's minimum contractual obligation within any annual period   44,000,000    
Cash paid for data processing, outsourcing services and other agreements   $ 29,000,000 14,000,000 $ 7,000,000
Minimum        
Commitments and Contingencies Disclosure [Line Items]        
Benefit continuation period   2 years    
Data Processing, Outsourcing Services And Other Agreements | Minimum        
Commitments and Contingencies Disclosure [Line Items]        
Data processing, outsourcing services and other agreements, expiration year   2021    
Data processing, outsourcing services and other agreements, estimated aggregate contractual obligation   $ 318,000,000    
Non cancelable contractual obligations within any annual period   $ 133,000,000    
Data Processing, Outsourcing Services And Other Agreements | Maximum        
Commitments and Contingencies Disclosure [Line Items]        
Data processing, outsourcing services and other agreements, expiration year   2027    
IBM Operations Support Services Agreement        
Commitments and Contingencies Disclosure [Line Items]        
Expected future year's minimum contractual obligation   $ 61,000,000    
Expected future year's minimum contractual obligation within any annual period   $ 37,000,000    
Canada        
Commitments and Contingencies Disclosure [Line Items]        
Pending claims, number | claim   5    
Pending national claims, number | claim   4    
Loss contingency, number of plaintiffs | plaintiff   19,000    
Cybersecurity Incident        
Commitments and Contingencies Disclosure [Line Items]        
Loss contingency, loss in period $ 380,500,000      
Additional contributions for unreimbursed costs and expenses   $ 125,000,000.0    
Cybersecurity Incident | Maximum        
Commitments and Contingencies Disclosure [Line Items]        
Settlement administration costs $ 80,500,000      
Cybersecurity Incident | GEORGIA        
Commitments and Contingencies Disclosure [Line Items]        
Pending claims, number | lawsuit   4    
Number of claims combined into a single claim | lawsuit   3    
Cybersecurity Incident, Investigation, Remediation, Legal, And Other Professional Services        
Commitments and Contingencies Disclosure [Line Items]        
Loss contingency, loss in period     $ 800,900,000