v2.4.0.8

Inventories - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Dec. 28, 2013	Dec. 29, 2012
Inventory Disclosure [Abstract]
Finished goods inventory held by distributors	$ 3.4	$ 3.0

X

- Definition

Inventory finished goods held by distributors.

+ References

No definition available.

+ Details

Name:	masi_InventoryFinishedGoodsHeldByDistributors
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_InventoryDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration