Income Taxes Income Taxes - Allocation of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Continuing operations	$ 258,400	$ 323,859	$ 431,761
Discontinued operations	99,768	(364,856)	24,052
Income tax (benefit) expense from continuing and discontinued operations	$ 358,168	$ (40,997)	$ 455,813

Amount of tax expense (benefit) attributable to income (loss) from operations classified as a discontinued operation. Excludes tax expense (benefit) for gain (loss) on disposal and for provision for gain (loss) until disposal.

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Period Type:	duration