Revenue Recognition and Valuation Accounts - Schedule of Allowance for Contractual Discounts and Estimated Uncompensated Care as a Percentage of Gross Segment Accounts Receivable (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Revenue Recognition And Valuation Accounts [Abstract]
Allowance for Contractual Discounts	60.00%	56.00%
Allowance for Uncompensated Care	18.00%	23.00%