Real Property Acquisitions and Development (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Development projects:
Development projects	$ 350,142	$ 173,074	$ 141,305
Expansion projects	10,336	11,363	38,808
Total construction in progress conversions	360,478	184,437	180,113
Triple Net [Member]
Development projects:
Development projects	283,472	46,094	104,844
Senior Housing Operating [Member]
Development projects:
Development projects	3,634	18,979	19,869
Outpatient Medical [Member]
Development projects:
Development projects	$ 63,036	$ 108,001	$ 16,592