SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Principles of Consolidation (Narrative) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) trust	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Selling, general and administrative expenses recorded to correct for accounting errors	$ 515,083	$ 438,654	$ 447,290	$ 450,619	$ 444,050	$ 421,700	$ 434,581	$ 425,568	$ 1,851,646	$ 1,725,899	$ 1,704,352
Interest expense	476,837	$ 470,250	$ 463,160	$ 455,337	$ 460,189	$ 459,852	$ 465,991	$ 463,950	$ 1,865,584	$ 1,849,982	$ 1,805,496
Number of trusts of which the Company is the beneficiary | trust									2
Expenses recorded to correct for accounting errors | Restatement Adjustment
Segment Reporting Information [Line Items]
Selling, general and administrative expenses recorded to correct for accounting errors	9,600
Interest expense	$ 1,400