Revenue Recognition and Valuation Accounts - Schedule of Allowance for Contractual Discounts and Estimated Uncompensated Care as a Percentage of Gross Segment Accounts Receivable (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Revenue Recognition And Valuation Accounts [Abstract]
Allowance for Contractual Discounts	57.00%	53.00%
Allowance for Uncompensated Care	21.00%	23.00%