SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION (Reconciliation of Real Estate and Accumulated Depreciation) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Real Estate
Balance at beginning of year	$ 5,355,409,000	$ 4,979,840,000	$ 4,774,632,000
Change in land	199,069,000	93,833,000	122,446,000
Additions	1,148,826,000	790,183,000	830,896,000
Impairments	0	0	(35,734,000)
Dispositions and write-offs and land costs of sales	(540,017,000)	(508,447,000)	(712,400,000)
Balance at end of year	6,163,287,000	5,355,409,000	4,979,840,000
Reconciliation of Accumulated Depreciation
Balance at beginning of year	321,882,000	245,814,000	232,969,000
Depreciation expense	113,518,000	116,401,000	81,878,000
Dispositions and write-offs	(54,508,000)	(40,333,000)	(69,033,000)
Balance at end of year	$ 380,892,000	$ 321,882,000	$ 245,814,000