Held for Sale and Discontinued Operations Schedule of Financial Results of DMG's Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net (loss) income from discontinued operations, net of tax	$ 9,980	$ 30,305
DMG held for sale | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	0	1,382,281
Expenses	0	1,338,153
(Loss) income from discontinued operations before taxes	0	44,128
Income tax expense	0	13,823
Coronavirus Aid Relief And Economic Security Act Additional Tax Benefit | DMG held for sale | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Business	$ 9,980	$ 0