Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		$ 3,062,923
Ending Balance		3,071,997
Total accumulated other comprehensive loss		3,062,923		$ 3,071,997	$ 3,062,923
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity				3,012,814	3,003,391
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		(56,767)	$ (22,023)
Unrealized income (loss)		16,314	(23,003)
Ending Balance		(40,453)	(45,026)
Total accumulated other comprehensive loss		(56,767)	(22,023)	(40,453)	(56,767)	$ (45,026)
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		(455)	(865)
Unrealized income (loss)		(25)	(1,955)
Reclassification adjustment	[1]	391	823
Ending Balance		(89)	(1,997)
Total accumulated other comprehensive loss		(455)	(865)	(89)	(455)	(1,997)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		(40,542)	(47,023)
Total accumulated other comprehensive loss		(40,542)	(47,023)	(40,542)		(47,023)
AOCI Attributable to Noncontrolling Interest [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Ending Balance		801	951
Total accumulated other comprehensive loss		801	$ 951	801		951
AOCI Attributable to Parent [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance		(56,031)
Ending Balance		(39,741)
Total accumulated other comprehensive loss		$ (56,031)		(39,741)	$ (56,031)
Total accumulated other comprehensive loss included in shareholders' equity/owners' equity				$ (39,741)		$ (46,072)

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