Relationship with Universal Health Realty Income Trust and Related Party Transactions - Additional Information (Detail)	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($)	Mar. 31, 2015 USD ($) Facility RenewalOption	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Related Party Transaction [Line Items]
Lease renewal period, years				5 years
Notice period on renewal of lease				90 days
Period of rights of refusal to leased facilities				180 days
Chief Executive Officer
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies				$ 25,000,000
Payments to acquire life insurance policies				1,300,000	$ 1,300,000
Chief Executive Officer | Trust Owned by Chief Executive Officer
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies				$ 8,000,000
Relationship with Universal Health Realty Income Trust
Related Party Transaction [Line Items]
Trust outstanding shares held, percentage	5.90%			5.90%
Advisory fee earned	$ 700,000		$ 700,000	$ 2,100,000	1,900,000
Pre-tax share of income from the Trust	100,000		1,700,000	1,100,000	2,100,000
Share of aggregate gain on fair value recognition included in the share of trust			1,600,000		1,600,000
Carrying value of investment in Trust	9,000,000			9,000,000		$ 9,300,000
Market value of investment in Trust	37,000,000			37,000,000		37,900,000
Aggregate construction cost/sales proceeds		$ 13,000,000
Aggregate rent expense paid		$ 900,000				1,100,000
Estimated purchase price of The Bridgeway's real property						$ 17,300,000
Rent expense under operating leases	$ 4,000,000		$ 4,000,000	$ 12,000,000	$ 12,000,000
Non-controlling ownership interests by subsidiaries	100.00%			100.00%
Relationship with Universal Health Realty Income Trust | Texas
Related Party Transaction [Line Items]
Number of free-standing emergency departments to be acquired | Facility		2
Lease agreement term		10 years
Number of renewal options at existing lease rates | RenewalOption		6
Renewal options term at existing lease rates		5 years
Renewal options term at fair market lease rates		5 years
Minimum
Related Party Transaction [Line Items]
Lease initial terms				13 years
Minimum | Chief Executive Officer
Related Party Transaction [Line Items]
Estimated death benefit proceeds				$ 33,000,000
Maximum
Related Party Transaction [Line Items]
Lease initial terms				15 years