Goodwill - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2015 USD ($) Segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Goodwill [Line Items]
Goodwill	$ 9,450,946,000	$ 9,415,295,000	$ 9,212,974,000
Goodwill impairment charge description	For example, a sustained, long-term reduction of 3% in operating income for HCP California, HCP Nevada and HCP New Mexico could reduce their estimated fair values by up to 1.8%, 1.9% and 2.0%, respectively. Separately, an increase in their respective discount rates of 100 basis points could reduce the estimated fair values of HCP California, HCP Nevada and HCP New Mexico by up to 4.2%, 3.1% and 3.6%, respectively.
Pre-tax goodwill impairment charge	$ 0
HealthCare Partners (HCP)
Goodwill [Line Items]
Number of reporting units | Segment	3
Goodwill	$ 3,586,390,000	$ 3,562,534,000	$ 3,516,162,000
HealthCare Partners (HCP) | Long-term Reduction of 3% Percent Operating Income
Goodwill [Line Items]
Decrease in operating income percentage used for assessment of fair values	3.00%
HealthCare Partners (HCP) | Increase In Discount Rates By 100 Basis Points
Goodwill [Line Items]
Increase in discount rates used for assessment of fair values	1.00%
HealthCare Partners (HCP) | California
Goodwill [Line Items]
Goodwill	$ 2,518,569,000
Percentage of Fair value in excess of carrying amount	9.90%
HealthCare Partners (HCP) | California | Long-term Reduction of 3% Percent Operating Income
Goodwill [Line Items]
Percentage of Fair value in excess of carrying amount	(1.80%)
HealthCare Partners (HCP) | California | Increase In Discount Rates By 100 Basis Points
Goodwill [Line Items]
Percentage of Fair value in excess of carrying amount	(4.20%)
HealthCare Partners (HCP) | Nevada
Goodwill [Line Items]
Goodwill	$ 517,618,000
Percentage of Fair value in excess of carrying amount	7.40%
HealthCare Partners (HCP) | Nevada | Long-term Reduction of 3% Percent Operating Income
Goodwill [Line Items]
Percentage of Fair value in excess of carrying amount	(1.90%)
HealthCare Partners (HCP) | Nevada | Increase In Discount Rates By 100 Basis Points
Goodwill [Line Items]
Percentage of Fair value in excess of carrying amount	(3.10%)
HealthCare Partners (HCP) | New Mexico
Goodwill [Line Items]
Goodwill	$ 71,684,000
Percentage of Fair value in excess of carrying amount	2.00%
HealthCare Partners (HCP) | New Mexico | Long-term Reduction of 3% Percent Operating Income
Goodwill [Line Items]
Percentage of Fair value in excess of carrying amount	(2.00%)
HealthCare Partners (HCP) | New Mexico | Increase In Discount Rates By 100 Basis Points
Goodwill [Line Items]
Percentage of Fair value in excess of carrying amount	(3.60%)