Segment Reporting - Cash Purchases of Property and Equipment (Details) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Segment Reporting Information [Line Items] |
|
|
|
| Total cash purchases of property and equipment, net |
$ 39,109
|
$ 33,439
|
$ 7,736
|
| Operating Segments |
|
|
|
| Segment Reporting Information [Line Items] |
|
|
|
| Total cash purchases of property and equipment, net |
34,896
|
27,902
|
6,527
|
| Operating Segments | Surgical facility services |
|
|
|
| Segment Reporting Information [Line Items] |
|
|
|
| Total cash purchases of property and equipment, net |
29,157
|
26,723
|
5,158
|
| Operating Segments | Ancillary services |
|
|
|
| Segment Reporting Information [Line Items] |
|
|
|
| Total cash purchases of property and equipment, net |
5,388
|
1,051
|
1,034
|
| Operating Segments | Optical services |
|
|
|
| Segment Reporting Information [Line Items] |
|
|
|
| Total cash purchases of property and equipment, net |
351
|
128
|
335
|
| General and administrative |
|
|
|
| Segment Reporting Information [Line Items] |
|
|
|
| Total cash purchases of property and equipment, net |
$ 4,213
|
$ 5,537
|
$ 1,209
|