Estimated Cost of Providing Uncompensated Care (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Health Care Trust Fund [Line Items]
Estimated cost of providing uncompensated care	$ 234,001	$ 239,620	$ 213,807
Charity Care
Health Care Trust Fund [Line Items]
Estimated cost of providing uncompensated care	94,088	120,208	107,887
Uninsured Discounts
Health Care Trust Fund [Line Items]
Estimated cost of providing uncompensated care	$ 139,913	$ 119,412	$ 105,920