Supplemental Balance Sheet and Income Statement Information - Reclass Accumulated Other (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Unrealized (gains) losses on available-for-sale securities that were reclassified from net income
Investment income (loss)	$ (3,198)	$ 9,677
Impairments and other charges	276,434
Interest expense	54,722	52,352
General and administrative expenses	57,384	68,167
Income (loss) from continuing operations before income taxes	(356,576)	(73,577)
Tax expense (benefit)	17,693	29,799
Net income (loss)	(374,362)	(103,533)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Unrealized (gains) losses on available-for-sale securities that were reclassified from net income
Interest expense	142	140
General and administrative expenses	52	54
Income (loss) from continuing operations before income taxes	(194)	(194)
Tax expense (benefit)	(47)	(46)
Net income (loss)	$ (147)	$ (148)