Business Combinations (Details) - Scenario, Forecast [Member] - Merger of AmSurg and Envision into New Amethyst [Member]	Dec. 31, 2016
AmSurg [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Number of shares to be issued for one share of acquiree's stock	1
AmSurg [Member] | Mandatory Convertible Preferred Stock [Member]
Business Acquisition [Line Items]
Number of shares to be issued for one share of acquiree's stock	1
Envision [Member]
Business Acquisition [Line Items]
Envision stockholders' percent of ownership in New Amethyst on date of merger	53.00%
Envision [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Number of shares to be issued for one share of acquiree's stock	0.334