XML 92 R79.htm IDEA: XBRL DOCUMENT v3.10.0.1
Commitments, Contingencies and Off-Balance Sheet Arrangements - Additional Information (Detail)
 3 Months Ended 9 Months Ended 201 Months Ended
Sep. 30, 2018
USD ($)
ft²
LetterOfCredit
Entity
Sep. 30, 2017
Entity
Sep. 30, 2018
USD ($)
ft²
LetterOfCredit
Entity
Employees
Sep. 30, 2017
Entity
Sep. 30, 2018
USD ($)
ft²
LetterOfCredit
Entity
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Number of square feet | ft² 360,000   360,000   360,000
Number of employees will accommodate at new facility | Employees     2,000    
Acquired property through lease area, sqft | ft²     306,000    
Acquired property through lease percentage of building     60.00%    
Operating lease commitment, expiration date     Feb. 28, 2018    
Number of companies acquired | Entity 38 31 95 89 488
Aggregate amount of maximum earnout obligations related to acquisitions $ 495,700,000   $ 495,700,000    
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet 219,600,000   $ 219,600,000    
Tax Increment Financing [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Property tax credit expect to receive period     15 years    
Economic development for growing economy tax credit 11,100,000   $ 11,100,000   $ 11,100,000
Letter of Credit [Member] | Collateral Related to Claim Funds [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Debt $ 1,300,000   $ 1,300,000   $ 1,300,000
Number of letters of credit issued | LetterOfCredit 1   1   1
Letter of Credit [Member] | Security Deposit [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Debt $ 500,000   $ 500,000   $ 500,000
Number of letters of credit issued | LetterOfCredit 1   1   1
Letter of Credit [Member] | Self-Insurance Deductibles [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Debt $ 9,700,000   $ 9,700,000   $ 9,700,000
Liabilities recorded on self-insurance $ 14,800,000   $ 14,800,000   $ 14,800,000
Number of letters of credit issued | LetterOfCredit 2   2   2
Letter of Credit [Member] | Rent-A-Captive Facility [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Debt $ 6,300,000   $ 6,300,000   $ 6,300,000
Number of letters of credit issued | LetterOfCredit 7   7   7
Minimum [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Ownership interest 1.00%   1.00%   1.00%
Minimum [Member] | Tax Increment Financing [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Property tax credit expect to receive $ 60,000,000   $ 60,000,000   $ 60,000,000
Maximum [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Ownership interest 50.00%   50.00%   50.00%
Maximum [Member] | Tax Increment Financing [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Property tax credit expect to receive $ 80,000,000   $ 80,000,000   $ 80,000,000
Brokerage [Member] | United Kingdom [Member]          
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]          
Sublease arrangement, term 10 years        
Sublease arrangement $ 22,000,000