Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Rental properties, net of accumulated depreciation of $741,334 and $635,535 at December 31, 2017 and 2016, respectively	$ 4,604,231	$ 3,595,762
Land held for development	33,692	22,530
Property under development	257,629	297,110
Mortgage Notes and Related Accrued Interest Receivable, Net	970,749	613,978
Investment in direct financing leases, net	57,903	102,698
Investment in joint ventures	5,602	5,972
Cash and cash equivalents	41,917	19,335
Restricted cash	17,069	9,744
Accounts receivable, net	93,693	98,939
Other assets	109,008	98,954
Total assets	6,191,493	4,865,022
Liabilities:
Accounts payable and accrued liabilities	136,929	119,758
Common dividends payable	25,203	20,367
Preferred dividends payable	4,982	5,951
Unearned rents and interest	68,227	47,420
Debt	3,028,827	2,485,625
Total liabilities	3,264,168	2,679,121
Equity:
Common Shares, $.01 par value; 100,000,000 shares authorized; and 76,858,632 and 66,263,487 shares issued at December 31, 2017 and 2016, respectively	769	663
Preferred shares, $.01 par value; 25,000,000 shares authorized:
Additional paid-in-capital	3,478,986	2,677,046
Treasury shares at cost: 2,733,552 and 2,616,406 common shares at December 31, 2017 and 2016, respectively	(121,591)	(113,172)
Accumulated other comprehensive income	12,483	7,734
Distributions in excess of net income	(443,470)	(386,509)
Equity	2,927,325	2,185,901
Total liabilities and equity	6,191,493	4,865,022
Series C Preferred Shares [Member]
Preferred shares, $.01 par value; 25,000,000 shares authorized:
Preferred shares	54	54
Series E Preferred Shares [Member]
Preferred shares, $.01 par value; 25,000,000 shares authorized:
Preferred shares	34	35
Series F Preferred Stock [Member]
Preferred shares, $.01 par value; 25,000,000 shares authorized:
Preferred shares	0	50
Series G Preferred Stock [Member]
Preferred shares, $.01 par value; 25,000,000 shares authorized:
Preferred shares	$ 60	$ 0