Segment Reporting - Summary of Assets by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Assets	$ 16,988,516	$ 17,311,394
Equity method and other investments	257,491	241,983
Property and equipment, net of accumulated depreciation	3,521,824	3,473,384
U.S. dialysis
ASSETS
Assets	15,344,647	15,778,880
Equity method and other investments	122,974	124,188
Other - Ancillary services
ASSETS
Assets	1,643,869	1,532,514
Equity method and other investments	134,517	117,795
International | Other - Ancillary services
ASSETS
Property and equipment, net of accumulated depreciation	$ 181,137	$ 154,572