Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Apr. 13, 2016
Business Combinations [Abstract]
Current assets			$ 455,016
Property, plant, and equipment, net			3,432,144
Goodwill	$ 1,490,797	$ 1,490,797	1,490,797
Other long-term assets			1,023,487
Less
Current liabilities			228,515
Net deferred income tax liabilities			1,059,939
Other deferred credits			279,379
Long-term debt, net			1,470,126
Total purchase price			$ 3,363,485

Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of deferred tax liability attributable to taxable temporary differences assumed at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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