Allowance for Uncollectible Accounts - Additional Information (Details)	Jun. 30, 2017	Dec. 31, 2016
Valuation of Qualifying Accounts [Abstract]
Allowance for Uncollectible Accounts Percent of Accounts Receivable	16.60%	18.90%
Days sales outstanding for receivables over 180 days old	46	49
Minimum age of patient accounts receivable used to calculate days sales outstanding	180