Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		$ 3,009,947
Ending Balance		2,921,979
Total accumulated other comprehensive loss		3,009,947		$ 2,921,979	$ 3,009,947
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity				2,866,810	2,952,928
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(17,256)	$ (5,823)
Unrealized loss		(23,003)	(6,229)
Ending Balance		(40,259)	(12,052)
Total accumulated other comprehensive loss		(17,256)	(5,823)	(40,259)	(17,256)	$ (12,052)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(865)	(377)
Unrealized loss		(1,955)	(2,592)
Reclassification adjustment	[1]	823	1,053
Ending Balance		(1,997)	(1,916)
Total accumulated other comprehensive loss		(865)	(377)	(1,997)	(865)	(1,916)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		(42,256)	(13,968)
Total accumulated other comprehensive loss		(42,256)	(13,968)	(42,256)		(13,968)
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		797	131
Total accumulated other comprehensive loss		797	$ 131	797		131
AOCI Attributable to Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(17,893)
Ending Balance		(41,459)
Total accumulated other comprehensive loss		$ (17,893)		(41,459)	$ (17,893)
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity				$ (41,459)		$ (13,837)

[1] Amounts reclassified out of Accumulated Other Comprehensive Loss/General & Limited Partner's Equity into contractual interest expense.