RECENT ACCOUNTING PRONOUNCEMENTS Lease Standard - Effect on Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net	$ 1,248,967		$ 1,242,058
Prepaid expenses and other current assets	149,025		178,313
Total current assets	1,571,448		1,567,710
Revenue earning equipment, net	10,561,011		9,415,961
Operating property and equipment, net	866,908		862,054
Sales-type leases and other assets			967,800
Total assets	14,522,054		13,347,808
Short-term debt and current portion of long-term debt	1,053,219		937,131
Accrued expenses and other current liabilities	819,876		847,739
Total current liabilities	2,641,149		2,516,746
Long-term debt	6,619,060		5,712,146
Other non-current liabilities	1,431,290		1,402,625
Deferred income taxes	1,222,849		1,179,723
Total liabilities	11,914,348		10,811,240
Retained earnings	2,385,620		2,337,252
Accumulated other comprehensive loss	(899,388)		(911,634)
Total shareholders' equity	2,607,706	$ 2,566,804	2,536,568	$ 2,460,859	$ 2,473,975	$ 2,453,577
Total liabilities and shareholders' equity	14,522,054		13,347,808
Sales-type leases and other assets	$ 992,846		967,802
Accounting Standards Update 2016-02 | As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net			1,219,400
Prepaid expenses and other current assets			201,600
Total current assets			1,568,400
Revenue earning equipment, net			9,498,000
Operating property and equipment, net			843,800
Sales-type leases and other assets			606,600
Total assets			13,051,100
Short-term debt and current portion of long-term debt			930,000
Accrued expenses and other current liabilities			630,500
Total current liabilities			2,292,300
Long-term debt			5,693,600
Other non-current liabilities			849,900
Deferred income taxes			1,304,800
Total liabilities			10,140,800
Retained earnings			2,710,700
Accumulated other comprehensive loss			(911,300)
Total shareholders' equity			2,910,300
Total liabilities and shareholders' equity			13,051,100
Accounting Standards Update 2016-02 | New Lease Standard Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings							$ 315,000
Lessor Adjustments | Accounting Standards Update 2016-02 | New Lease Standard Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net			22,600
Prepaid expenses and other current assets			(23,300)
Total current assets			(700)
Revenue earning equipment, net			(84,200)
Operating property and equipment, net			0
Sales-type leases and other assets			156,800
Total assets			72,000
Short-term debt and current portion of long-term debt			0
Accrued expenses and other current liabilities			145,100
Total current liabilities			145,100
Long-term debt			0
Other non-current liabilities			421,200
Deferred income taxes			(124,600)
Total liabilities			441,700
Retained earnings			(369,600)
Accumulated other comprehensive loss			(100)
Total shareholders' equity			(369,700)
Total liabilities and shareholders' equity			72,000
Lessee Adjustments | Accounting Standards Update 2016-02 | New Lease Standard Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net			0
Prepaid expenses and other current assets			0
Total current assets			0
Revenue earning equipment, net			2,200
Operating property and equipment, net			18,200
Sales-type leases and other assets			204,300
Total assets			224,700
Short-term debt and current portion of long-term debt			7,200
Accrued expenses and other current liabilities			72,200
Total current liabilities			79,300
Long-term debt			18,500
Other non-current liabilities			131,500
Deferred income taxes			(500)
Total liabilities			228,800
Retained earnings			(3,800)
Accumulated other comprehensive loss			(200)
Total shareholders' equity			(4,100)
Total liabilities and shareholders' equity			224,700
Prior Period Error | New Lease Standard Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net			24,000
Revenue earning equipment, net			83,000
Sales-type leases and other assets			$ 65,000