Segment Disclosures - Revenues and Assets by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Disclosure
Total revenues	$ 492,168	$ 520,457
Operating segment
Segment Disclosure
Total revenues	492,168	520,457
Operating segment | SH NNN
Segment Disclosure
Total revenues	100,034	106,889
Operating segment | SHOP
Segment Disclosure
Total revenues	140,228	165,763
Operating segment | Life science
Segment Disclosure
Total revenues	85,321	88,948
Operating segment | Medical office
Segment Disclosure
Total revenues	118,371	108,023
Operating segment | Other Non-reportable segments
Segment Disclosure
Total revenues	$ 48,214	$ 50,834