XML 57 R31.htm IDEA: XBRL DOCUMENT v3.20.4
Accounting Policies (Details)
 12 Months Ended
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Oct. 01, 2019
USD ($)
Jan. 01, 2019
USD ($)
Dec. 31, 2017
USD ($)
Oct. 01, 2010
USD ($)
Sep. 30, 2010
USD ($)
Disaggregation of Revenue [Line Items]                    
Revenues(1) [1] $ 4,287,004,000 $ 4,314,804,000 $ 3,828,549,000              
Segment Reporting [Abstract]                    
Number of reportable segments (integer) 1                  
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross       $ 495,078,000 $ 403,301,000          
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment       (278,822,000) (255,595,000)          
Property, Plant and Equipment, Net       216,256,000 147,706,000          
Amortization of capitalized computer software costs $ 8,700,000 7,800,000 6,000,000.0              
Unamortized computer software costs       32,600,000 25,800,000          
Leases [Abstract]                    
Right-of-use “ROU” leased assets       60,663,000 56,886,000   $ 50,800,000      
Operating Lease, Liability       80,807,000     $ 63,700,000      
Goodwill and Intangible Assets Disclosure [Abstract]                    
Goodwill, Impairment Loss $ 0                  
Goodwill, Gross       21,200,000            
Goodwill, Impaired, Accumulated Impairment Loss       (8,500,000)            
Goodwill       12,700,000            
Health Insurance Costs [Abstract]                    
Number of days cash in advance of beginning of reporting quarter United establishes cash funding rates 90 days                  
Prepaid health insurance       9,000,000 9,000,000          
Required deposit for health care costs       6,500,000            
Amount which Plan Costs were less than the net premiums paid and owed       (6,000,000.0)            
Portion of insurance costs that is less than the agreed upon surplus included in accrued health insurance costs a cnt liab       (15,000,000.0)            
Premiums owed to United       (11,700,000)            
Benefits Costs Incurred Related to Run-off     (1,300,000) (200,000) 2,300,000          
Workers' Compensation Costs [Abstract]                    
Company's maximum economic burden for the first layer of claims per occurrence           $ 1,500,000       $ 1,000,000
Company's maximum aggregate economic burden for claims in excess of $1 million per policy year           $ 6,000,000     $ 6,000,000  
Reduction in accrued workers' compensation costs for changes in estimated losses $ 42,100,000 $ 31,700,000 18,800,000              
U.S. Treasury rates that correspond with the weighted average estimated claim payout period (in hundredths) 0.60% 1.90%                
Restricted Cash and Cash Equivalents, Current     42,227,000 45,522,000 49,295,000     $ 41,137,000    
Deposits workers' compensation     166,474,000 186,331,000 175,913,000     154,215,000    
Incurred but not paid workers' compensation liabilities                    
Liability for Unpaid Claims and Claims Adjustment Expense, Adjustments     229,639,000   242,904,000          
Accrued claims $ 42,639,000 $ 62,552,000                
Present value discount, net of accretion 740,000 (3,643,000)                
Paid claims (45,522,000) (45,644,000)                
Ending balance 240,761,000 242,904,000                
Current portion of accrued claims       45,522,000 49,295,000          
Long-term portion of accrued claims       195,239,000 193,609,000          
Ending Balance 240,761,000 242,904,000   240,761,000 242,904,000          
Current portion of workers' compensation administrative fees accrued       2,700,000 3,600,000          
Undiscounted accrued workers' compensation costs $ 257,900,000 262,900,000                
Time period incurred claims expected to be paid recorded as restricted cash 1 year                  
Return Of Excess Claim Funds $ 28,200,000                  
Deposits workers' compensation     166,474,000 $ 186,331,000 175,913,000     $ 154,215,000    
Time period estimate of incurred claim costs to be paid included in short term liabilities 1 year                  
Stock-Based Compensation [Abstract]                    
Number of stock-based employee compensation plans       1            
Percentage of annual grants issued to directors that are vested (in hundredths) 100.00%                  
Vesting period for officers and other management to be eligible for restricted stock grants, minimum 3 years                  
Percentage of grants issued to directors that are vested for annual award grants. 100.00%                  
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]                    
Percentage of our health insurance coverage provided by United       87.00%            
Corporate Employees [Member]                    
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]                    
Percentage the entity matches of eligible corporate employees' contributions 100.00%                  
Percentage of eligible compensation matched, maximum 6.00%                  
Matching contributions to the plan $ 12,600,000 11,400,000 10,300,000              
Worksite Employees [Member]                    
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]                    
Percentage of eligible compensation matched, Minimum 0.00%                  
Percentage of eligible compensation matched, maximum 6.00%                  
Matching contributions to the plan $ 199,200,000 198,200,000 165,500,000              
Land [Member]                    
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross       $ 6,215,000 6,215,000          
Building and Building Improvements [Member]                    
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross       125,704,000 119,635,000          
Building and Building Improvements [Member] | Minimum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 5 years                  
Building and Building Improvements [Member] | Maximum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 32 years                  
Computer hardware and software [Member]                    
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross       129,213,000 123,232,000          
Computer hardware and software [Member] | Minimum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 2 years                  
Computer hardware and software [Member] | Maximum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 5 years                  
Software Development Costs [Member]                    
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross       100,762,000 85,252,000          
Software Development Costs [Member] | Minimum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 3 years                  
Software Development Costs [Member] | Maximum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 3 years                  
Furniture, Fixtures and Other [Member]                    
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross       48,516,000 48,082,000          
Furniture, Fixtures and Other [Member] | Minimum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 5 years                  
Furniture, Fixtures and Other [Member] | Maximum [Member]                    
Property, Plant and Equipment [Line Items]                    
Estimated useful lives of property and equipment 7 years                  
Construction in Progress [Member]                    
Property, Plant and Equipment [Line Items]                    
Property, Plant and Equipment, Gross [2]       $ 84,668,000 $ 20,885,000          
Northeast [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues(1) $ 1,189,837,000 1,135,771,000 996,541,000              
Southeast [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues(1) 509,846,000 499,201,000 447,584,000              
Central [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues(1) 761,905,000 743,514,000 637,779,000              
Southwest [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues(1) 935,634,000 1,001,845,000 895,243,000              
West [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues(1) 839,347,000 880,434,000 797,942,000              
Other Revenues [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues(1) $ 50,435,000 $ 54,039,000 $ 53,460,000              
[1] Revenues are comprised of gross billings less worksite employee (“WSEE”) payroll costs as follows:
Year ended December 31,
(in thousands)
202020192018
Gross billings
$28,168,611 $27,212,010 $23,830,731 
Less: WSEE payroll cost
23,881,607 22,897,206 20,002,182 
Revenues
$4,287,004 $4,314,804 $3,828,549 
[2] Construction in progress is related to our corporate office expansion.