Sale of Businesses (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) hospital
Sale of Businesses
Gain on disposal	$ 35.6
Contract Therapy | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member]
Sale of Businesses
Gain on disposal	33.9
Total consideration from sale of businesses	65.0
Outpatient Rehabilitation | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member]
Sale of Businesses
Gain on disposal	$ 1.7
Outpatient Rehabilitation | Disposed by Sale
Sale of Businesses
Number of businesses sold | hospital	9