Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Payor refunds and retractions	$ 292,370	$ 270,298
Insurance and self-insurance accruals	64,924	76,857
Accrued interest	83,362	82,234
Accrued non-income tax liabilities	28,317	23,643
Other	83,689	125,860
Other liabilities	$ 552,662	$ 578,892