Summary of Significant Accounting Policies (Reconciliation of Basic and Diluted Net Income Per Share) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jul. 02, 2011	Jul. 03, 2010	Jul. 02, 2011	Jul. 03, 2010
Summary of Significant Accounting Policies
Net income including noncontrolling interests	$ 16,909	$ 13,916	$ 35,063	$ 40,080
Net (income) loss attributable to the noncontrolling interests	129	371	(12)	917
Net income attributable to Masimo Corporation	$ 17,038	$ 14,287	$ 35,051	$ 40,997
Weighted average shares outstanding - basic	59,842	58,798	59,720	58,532
Basic net income per share attributable to Masimo Corporation	$ 0.28	$ 0.24	$ 0.59	$ 0.70
Diluted share equivalent: stock options	1,390	1,712	1,376	1,964
Weighted average shares outstanding - diluted	61,232	60,510	61,096	60,496
Diluted net income per share attributable to Masimo Corporation	$ 0.28	$ 0.24	$ 0.57	$ 0.68