DEBT - Schedule of Long-Term Debt (Parenthetical) (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
$1.2 billion senior credit facility weighted average rate 3.45% at 2018 and 2.55% at 2017, due in 2022
Debt Instrument [Line Items]
Maximum borrowing capacity of line of credit facility	$ 1,200,000,000
Long-term debt, weighted average interest rate	3.45%	2.55%
$950 million term loan weighted average rate 3.45% at 2018 and 2.83% at 2017, due in 2022
Debt Instrument [Line Items]
Maximum borrowing capacity of line of credit facility	$ 950,000,000
Stated interest rate	3.45%	2.83%
$125 million private placement notes 3.18% at 2018 and 2.68% at 2017, due in 2019
Debt Instrument [Line Items]
Stated interest rate	3.18%	2.68%
Long-term debt, face amount	$ 125,000,000
$225 million private placement notes 4.97% at 2018 and 4.47% at 2017, due in 2020
Debt Instrument [Line Items]
Stated interest rate	4.97%	4.47%
Long-term debt, face amount	$ 225,000,000
$150 million private placement notes 3.39% at 2018 and 2.89% at 2017, due in 2021
Debt Instrument [Line Items]
Stated interest rate	3.39%	2.89%
Long-term debt, face amount	$ 150,000,000
$125 million private placement notes 3.76% at 2018 and 3.26% at 2017, due in 2022
Debt Instrument [Line Items]
Stated interest rate	3.76%	3.26%
Long-term debt, face amount	$ 125,000,000
$200 million private placement notes 3.22% at 2018 and 2.72% at 2017, due in 2022
Debt Instrument [Line Items]
Stated interest rate	3.22%	2.72%
Long-term debt, face amount	$ 200,000,000
$100 million private placement notes 3.29% at 2018 and 2.79% at 2017, due in 2023
Debt Instrument [Line Items]
Stated interest rate	3.29%	2.79%
Long-term debt, face amount	$ 100,000,000
$150 million private placement notes 3.68% at 2018 and 3.18% at 2017, due in 2023
Debt Instrument [Line Items]
Stated interest rate	3.68%	3.18%
Long-term debt, face amount	$ 150,000,000
Promissory notes and deferred consideration weighted average rate 1.69% at 2018 and 1.49% at 2017 and weighted average maturity 3.0 years at 2018 and 2.9 years at 2017
Debt Instrument [Line Items]
Long-term debt, weighted average interest rate	1.69%	1.49%
Long-term debt, maturity	3 years	2 years 10 months 24 days
Foreign bank debt weighted average rate 5.37% at 2018 and 6.11% at 2017 and weighted average maturity 2.5 years at 2018 and 1.7 years at 2017
Debt Instrument [Line Items]
Long-term debt, weighted average interest rate	5.37%	6.11%
Long-term debt, maturity	2 years 6 months	1 year 8 months 12 days