Investments in and Advances to Unconsolidated Joint Ventures - Equity Method Investments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 827,202	$ 571,491
CCRC JV | SHOP
Company owned interests in entities, accounted under equity method:
Number of unconsolidated joint ventures | item	2
CCRC JV | SHOP
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 434,649	439,449
Investment ownership percentage	49.00%
RIDEA II | SHOP
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 263,180
Investment ownership percentage	40.00%
MBK JV | SHOP
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 39,088	38,909
Investment ownership percentage	50.00%
MBK Development JV | SHOP
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 2,464	2,463
Investment ownership percentage	50.00%
MBK JV and MBK Development JV | SHOP
Company owned interests in entities, accounted under equity method:
Number of unconsolidated joint ventures | item	2
HCP Ventures IV, LLC | Medical office
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 7,338	7,277
Investment ownership percentage	20.00%
HCP Life Science | Life science
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 65,490	67,879
Number of unconsolidated joint ventures | item	3
HCP Life Science | Life science | Minimum
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	50.00%
HCP Life Science | Life science | Maximum
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	63.00%
Torrey Pines Science Center, LP | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	50.00%
Britannia Biotech Gateway, LP | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	55.00%
LASDK, LP | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	63.00%
Vintage Park Development JV | SHOP
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 6,953	7,486
Investment ownership percentage	85.00%
Suburban Properties, LLC | Medical office
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 4,618	4,628
Investment ownership percentage	67.00%
K&Y
Company owned interests in entities, accounted under equity method:
Number of unconsolidated joint ventures | item	3
K&Y | Other Non-reportable segments
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 1,380	1,342
Investment ownership percentage	80.00%
Advances to unconsolidated joint ventures, net
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 2,042	$ 2,058