Allowance for Uncollectible Accounts - Additional Information (Details)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Valuation of Qualifying Accounts [Abstract]
Allowance for Uncollectible Accounts Percent of Accounts Receivable	15.20%	18.90%
Decrease in patient accounts receivable over 180 days during the reporting period due to process improvements	17.00%
Age of patient accounts receivable used to calculate collection process improvements	180 days