Investments in and Advances to Unconsolidated Joint Ventures - Schedule of Equity Method Investments (Details) $ in Thousands	Jun. 30, 2017 USD ($) joint_venture	Dec. 31, 2016 USD ($)
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 829,231	$ 571,491
CCRC JV | SHOP
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	49.00%
Investments in and advances to unconsolidated joint ventures	$ 433,507	439,449
Number of unconsolidated joint ventures | joint_venture	2
RIDEA II | SHOP
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	40.00%
Investments in and advances to unconsolidated joint ventures	$ 258,505	0
HCP Life Science | Life science
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 64,795	67,879
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%
MBK JV | SHOP
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	50.00%
Investments in and advances to unconsolidated joint ventures	$ 38,806	38,909
Medical Office JVs | Medical office
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 13,569	13,438
Number of unconsolidated joint ventures | joint_venture	3
Medical Office JVs | Medical office | Minimum
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	20.00%
Medical Office JVs | Medical office | Maximum
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	67.00%
HCP Ventures VI, LLC | Medical office
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	20.00%
H C P Ventures III, LLC | Medical office
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	30.00%
Suburban Properties, LLC | Medical office
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	67.00%
Development JVs | SHOP
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 18,616	10,459
Number of unconsolidated joint ventures | joint_venture	4
Development JVs | SHOP | Minimum
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	50.00%
Development JVs | SHOP | Maximum
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	90.00%
Vintage Park Development JV | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	85.00%
Waldwick | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	85.00%
Otay Ranch | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	90.00%
MBK Development JV | Life science
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	50.00%
K&Y JVs | Other non-reportable segments
Company owned interests in entities, accounted under equity method:
Investment ownership percentage	80.00%
Investments in and advances to unconsolidated joint ventures	$ 1,420	1,342
Advances to unconsolidated joint ventures, net
Company owned interests in entities, accounted under equity method:
Investments in and advances to unconsolidated joint ventures	$ 13	$ 15