SUMMARY OF QUARTERLY RESULTS (UNAUDITED) (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Provisions for uncollectible accounts and impairment losses on real estate properties and direct financing leases	$ 30,600	$ 20,900	$ (500)	$ 12,700	$ 64,600	$ 224,400	$ 12,800	$ 10,000
Net gain (loss) on assets sold	$ 15,500	$ (5,400)	$ (2,900)	$ 17,500	$ 46,400	$ 700	$ (600)	$ 7,400	$ 24,774	$ 53,912	$ 50,208