Variable Interest Entity - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended	1 Months Ended	12 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Sep. 28, 2012	Apr. 30, 2010 C P T C	Sep. 28, 2012 Scripps Proton Therapy Center	Sep. 28, 2012 Scripps Proton Therapy Center Maximum
Variable Interest Entity [Line Items]
Equity CPTC has raised			$ 60
Loan facility to CPTC	165.3
Value of CPTC proton therapy system agreement				88
Duration of CPTC proton therapy system service agreement		10 years
Approximate value of CPTC proton therapy system service agreement		60
CPTC loan facility, Varian's maximum loan commitment	115.3
Pro rata share of the Company's obligation to fund the initial distribution and subsequent advances	69.75%
Loan to CPTC	19.2		49.7
CPTC loan facility, end of the drawdown period	2014
CPTC loan facility, maturity			2015-09
CPTC loan facility, interest rate margin during initial term			6.25%
CPTC loan facility, minimum interest rate during initial term			8.25%
CPTC loan facility, interest rate margin during extension term			7.00%
CPTC loan facility, minimum interest rate during extension term			9.00%
CPTC loan facility, description of interest and principal payments			The loan, which matures in September 2015, bears interest at LIBOR plus 6.25% per annum with a minimum interest rate of 8.25% per annum. The loan can be extended for two additional one-year terms at the election of CPTC during which extensions interest will accrue at LIBOR plus 7.00% per annum with a minimum interest rate of 9.00% per annum.
CPTC loan facility, amortization period over which monthly payments are calculated after July 1, 2014			15 years
CPTC loan facility, interest rate based on which monthly payments are calculated after July 1, 2014			8.25%
CPTC loan facility, commitment fee as a % of loan facility amount			1.50%
CPTC loan facility, exit fee as a % of principal paid			1.00%
The Company's subsidiary right to share revenues of the Scripps Proton Therapy Center (%)					4.00%
The Company's subsidiary right to share revenues of the Scripps Proton Therapy Center (period)					35 years
Loan repayment amount that results in reduction of revenue share					71
The Company's subsidiary right to share revenues of the Scripps Proton Therapy Center upon repayment of loan amount (%)						1.00%
Accounts receivable from CPTC	$ 15.2		$ 30.7