XML 87 R39.htm IDEA: XBRL DOCUMENT v3.20.4
DESCRIPTION OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)
 12 Months Ended
Dec. 31, 2020
USD ($)
reporting_unit
segment
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Jan. 01, 2018
USD ($)
Dec. 31, 2017
USD ($)
Summary Of Significant Accounting Policy [Line Items]          
Number of reportable segments | segment 1        
Cumulative effect adjustment to opening retained earnings upon adoption $ 607,000,000 $ 475,000,000 $ 375,000,000   $ 206,000,000
Client deposits and other client liabilities 134,000,000 44,000,000      
Advance collection 24,000,000 95,000,000      
Maximum reimbursement per claim occurrence $ 1,000,000        
Plan years to be settled 10 years        
Prepaid Insurance $ 49,000,000 39,000,000      
Weighted-average rate used in discounting the lease liabilities 4.00%        
Accounts receivable allowance for doubtful accounts $ 0 0      
Number of reporting units | reporting_unit 1        
Impairment of goodwill $ 0 0 0    
Impairment of finite-lived intangible assets 0 0 0    
Advertising costs 19,000,000 18,000,000 17,000,000    
Bad debt expense net of recoveries 1,000,000 0 0    
Accumulated Deficit:          
Summary Of Significant Accounting Policy [Line Items]          
Cumulative effect adjustment to opening retained earnings upon adoption $ (144,000,000) (219,000,000) (266,000,000)   (377,000,000)
Cumulative Effect, Period of Adoption, Adjustment | Accumulated Deficit:          
Summary Of Significant Accounting Policy [Line Items]          
Cumulative effect adjustment to opening retained earnings upon adoption   (1,000,000) $ 0   $ 2,000,000
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2014-09 | Accumulated Deficit:          
Summary Of Significant Accounting Policy [Line Items]          
Cumulative effect adjustment to opening retained earnings upon adoption       $ 2,000,000  
Minimum          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of intangible assets 1 year        
Minimum | Software Development          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of intangible assets 3 years        
Minimum | Software And Office Equipment          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of property and equipment 3 years        
Minimum | Furniture, fixtures, and equipment          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of property and equipment 5 years        
Maximum          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of intangible assets 10 years        
Maximum | Software Development          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of intangible assets 5 years        
Maximum | Software And Office Equipment          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of property and equipment 5 years        
Maximum | Furniture, fixtures, and equipment          
Summary Of Significant Accounting Policy [Line Items]          
Estimated useful life of property and equipment 7 years        
Non-US | Geographic Concentration Risk | Revenue          
Summary Of Significant Accounting Policy [Line Items]          
Concentration risk percentage 1.00%        
Health Care          
Summary Of Significant Accounting Policy [Line Items]          
Prepaid Insurance $ 58,000,000 $ 52,000,000