Relationship with Universal Health Realty Income Trust and Related Party Transactions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transaction [Line Items]
Lease renewal period, years	5
Notice period on renewal of lease	90
Period of rights of refusal to leased facilities	180
Minimum
Related Party Transaction [Line Items]
Lease initial terms	13
Maximum
Related Party Transaction [Line Items]
Lease initial terms	15
Chief Executive Officer
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies	$ 25
Estimated death benefit proceeds	33
Payments to acquire life insurance policies	1.4	1.4	6.0
Net of tax present value of projected premium funding commitment	9
Chief Executive Officer | Trust Owned by Chief Executive Officer
Related Party Transaction [Line Items]
Estimated payments to acquire life insurance policies	8
Relationship with Universal Health Realty Income Trust
Related Party Transaction [Line Items]
Trust outstanding shares held, percentage	6.20%
Advisory fee earned	2.1	2.0	1.8
Pre-tax share of income from the Trust	1.2	4.6	1.0
Share of income included in the share of trust		3.7
Current ownership percentage of the trust		100.00%
Carrying value of investment in Trust	9.3	9.9
Market value of investment in Trust	39.9	30.7
Rent expense under operating leases	$ 16.3	$ 16.3	$ 16.2
Non-controlling ownership interests by subsidiaries	100.00%