Consolidated Statement Of Changes In Equity - 3 months ended Mar. 31, 2016 - USD ($) shares in Thousands, $ in Thousands	General Partner Common Units [Member]	Limited Partners Common Units [Member]	General Partner Common Unitholders [Member]	Limited Partner Common Unitholders [Member]	Accumulated Other Comprehensive Income [Member]	Noncontrolling Interest In Consolidated Joint Ventures [Member]	Total
Balance, units at Dec. 31, 2015	89,584
Balance, value at Dec. 31, 2015		$ 10,517	$ 1,399,419	$ 227,148		$ 57,141	$ 1,683,708
Net income (loss)			62,191	7,284		(706)	68,769
Distributions			(13,446)	(1,601)			(15,047)
Increase in noncontrolling interest						997	997
Redemption of limited partner common units for shares of general partner common units, units	17
Redemption of limited partner common units for shares of general partner common units, value		(17)	276	(276)
Shares issued under Dividend Reinvestment and Stock Purchase Plan, value			10				10
Directors' deferred compensation plan			101				101
Stock compensation, units	37
Stock compensation, value			612	173			785
Other comprehensive income (loss)				(665)	$ (5,675)		(6,340)
Balance, units at Mar. 31, 2016	89,638
Balance, value at Mar. 31, 2016		$ 10,500	$ 1,449,163	$ 232,063	$ (5,675)	$ 57,432	$ 1,732,983