Estimated Cost of Providing Uncompensated Care (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Health Care Trust Fund [Line Items]
Estimated cost of providing uncompensated care	$ 213,807	$ 184,187	$ 172,959
Charity Care
Health Care Trust Fund [Line Items]
Estimated cost of providing uncompensated care	107,887	77,557	78,475
Uninsured Discounts
Health Care Trust Fund [Line Items]
Estimated cost of providing uncompensated care	$ 105,920	$ 106,630	$ 94,484