Basis of Presentation and Significant Accounting Policies - Effects of Adopting Topic 842 (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets
Other current assets	$ 305,246	$ 258,908	$ 274,857
Property, plant and equipment, net	11,229,197	10,732,909	11,026,020
Operating lease right-of-use assets	1,483,491	1,468,762	0
Intangible assets, net	2,127,843	2,310,091	2,333,296
Other assets	499,632	469,784	533,252
Liabilities
Current portion of operating lease liabilities	137,002	144,405	0
Current portion of finance lease liabilities	65,518	70,795	0
Current portion of capital lease and other financing obligations		0	77,844
Other current liabilities	119,976	120,540	126,995
Operating lease liabilities, less current portion	1,333,901	1,312,262	0
Finance lease liabilities, less current portion	1,301,482	1,165,188	0
Capital lease and other financing obligations, less current portion		0	1,441,077
Other liabilities	558,912	541,491	629,763
Equity
Retained Earnings	$ 1,266,430	883,975	$ 889,948
Topic 842
Assets
Other current assets		(15,949)
Property, plant and equipment, net		(293,111)
Operating lease right-of-use assets		1,468,762
Intangible assets, net		(23,205)
Other assets		(63,468)
Liabilities
Current portion of operating lease liabilities		144,405
Current portion of finance lease liabilities		70,795
Current portion of capital lease and other financing obligations		(77,844)
Other current liabilities		(6,455)
Operating lease liabilities, less current portion		1,312,262
Finance lease liabilities, less current portion		1,165,188
Capital lease and other financing obligations, less current portion		(1,441,077)
Other liabilities		(88,272)
Equity
Retained Earnings		$ (5,973)