Consolidated Statement of Changes in Partner Capital Statement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net (loss) income	$ (24,783)	$ 91,493
Other comprehensive income (loss)
Amounts reclassified from accumulated other comprehensive loss	1,425	(176)
Contributions from partners	100	895
Issuance of exchangeable operating partnership units	1,275
Distributions to partners	(1,164)	(1,565)
Reallocation of limited partner's interest		0
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	3,764	3,952
Partners Capital Total [Member]
Net (loss) income	(25,332)	90,446
Other comprehensive income (loss)
Amounts reclassified from accumulated other comprehensive loss	1,404	(152)
Reallocation of limited partner's interest		66
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	3,764	3,952
Partnership Interest [Member]
Beginning Balance	6,289,961	6,450,168
Net (loss) income	(24,783)	91,493
Other comprehensive income (loss)
Other comprehensive loss before reclassification	(16,064)	(5,352)
Amounts reclassified from accumulated other comprehensive loss	1,425	(176)
Contributions from partners	100
Deferred compensation plan, net		895
Issuance of exchangeable operating partnership units	1,275
Distributions to partners	(101,407)	(99,761)
Reallocation of limited partner's interest		0
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	3,764	3,952
Common units repurchased and retired as a result of common stock repurchased and retired by Parent Company		(32,778)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	125,773
Common units issued as a result of common stock issued by Parent Company, net of repurchases		(5,668)
Common units redeemed as a result of common stock redeemed by Parent Company, net of issuances	(4,809)
Ending Balance	6,275,235	6,402,773
Partnership Interest [Member] | Partners Capital Total [Member]
Beginning Balance	6,249,448	6,408,636
Net (loss) income	(25,447)	90,636
Other comprehensive income (loss)
Other comprehensive loss before reclassification	(15,005)	(5,027)
Amounts reclassified from accumulated other comprehensive loss	1,410	(153)
Contributions from partners	0
Deferred compensation plan, net		0
Issuance of exchangeable operating partnership units	1,275
Distributions to partners	(100,243)	(98,196)
Reallocation of limited partner's interest		(66)
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	3,764	3,952
Common units repurchased and retired as a result of common stock repurchased and retired by Parent Company		(32,778)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	125,773
Common units issued as a result of common stock issued by Parent Company, net of repurchases		(5,668)
Common units redeemed as a result of common stock redeemed by Parent Company, net of issuances	(4,809)
Ending Balance	6,236,166	6,361,336
Partnership Interest [Member] | AOCI Attributable to Parent [Member]
Beginning Balance	(11,997)	(927)
Net (loss) income	0	0
Other comprehensive income (loss)
Other comprehensive loss before reclassification	(14,938)	(5,017)
Amounts reclassified from accumulated other comprehensive loss	1,404	(152)
Contributions from partners	0
Deferred compensation plan, net		0
Issuance of exchangeable operating partnership units	0
Distributions to partners	0	0
Reallocation of limited partner's interest		0
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	0	0
Common units repurchased and retired as a result of common stock repurchased and retired by Parent Company		0
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	0
Common units issued as a result of common stock issued by Parent Company, net of repurchases		0
Common units redeemed as a result of common stock redeemed by Parent Company, net of issuances	0
Ending Balance	(25,531)	(6,096)
Partnership Interest [Member] | Noncontrolling Interest [Member]
Beginning Balance	40,513	41,532
Net (loss) income	664	857
Other comprehensive income (loss)
Other comprehensive loss before reclassification	(1,059)	(325)
Amounts reclassified from accumulated other comprehensive loss	15	(23)
Contributions from partners	100
Deferred compensation plan, net		895
Issuance of exchangeable operating partnership units	0
Distributions to partners	(1,164)	(1,565)
Reallocation of limited partner's interest		66
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	0	0
Common units repurchased and retired as a result of common stock repurchased and retired by Parent Company		0
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	0
Common units issued as a result of common stock issued by Parent Company, net of repurchases		0
Common units redeemed as a result of common stock redeemed by Parent Company, net of issuances	0
Ending Balance	39,069	41,437
Partnership Interest [Member] | General Partner [Member]
Beginning Balance	6,225,345	6,398,897
Net (loss) income	(25,332)	90,446
Other comprehensive income (loss)
Other comprehensive loss before reclassification	0	0
Amounts reclassified from accumulated other comprehensive loss	0	0
Contributions from partners	0
Deferred compensation plan, net		0
Issuance of exchangeable operating partnership units	0
Distributions to partners	(99,788)	(97,992)
Reallocation of limited partner's interest		(66)
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	3,764	3,952
Common units repurchased and retired as a result of common stock repurchased and retired by Parent Company		(32,778)
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	125,773
Common units issued as a result of common stock issued by Parent Company, net of repurchases		(5,668)
Common units redeemed as a result of common stock redeemed by Parent Company, net of issuances	(4,809)
Ending Balance	6,224,953	6,356,791
Partnership Interest [Member] | Limited Partner [Member]
Beginning Balance	36,100	10,666
Net (loss) income	(115)	190
Other comprehensive income (loss)
Other comprehensive loss before reclassification	(67)	(10)
Amounts reclassified from accumulated other comprehensive loss	6	(1)
Contributions from partners	0
Deferred compensation plan, net		0
Issuance of exchangeable operating partnership units	1,275
Distributions to partners	(455)	(204)
Reallocation of limited partner's interest		0
Restricted units issued as a result of restricted stock issued by Parent Company, net of amortization	0	0
Common units repurchased and retired as a result of common stock repurchased and retired by Parent Company		0
Common units issued as a result of common stock issued by Parent Company, net of issuance costs	0
Common units issued as a result of common stock issued by Parent Company, net of repurchases		0
Common units redeemed as a result of common stock redeemed by Parent Company, net of issuances	0
Ending Balance	$ 36,744	$ 10,641