Variable Interest Entity - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended		9 Months Ended		1 Months Ended	9 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Jun. 28, 2013	Sep. 28, 2012	Apr. 30, 2010 CPTC	Jun. 28, 2013 Scripps Proton Therapy Center	Jun. 28, 2013 Scripps Proton Therapy Center Maximum
Variable Interest Entity [Line Items]
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			59.5	49.7
CPTC loan facility, end of the drawdown period	2014
Loan facility to CPTC	165.3
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 the London Interbank Offer Rate (“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
The company's subsidiary right to share revenues of the Scripps Proton Therapy Center upon repayment of the Company's loan amount (%)							1.00%
Loan repayment amount that results in reduction of revenue shares						71
Accounts receivable from CPTC			$ 40.3	$ 30.7