Summary of Estimated Fair Values of Separately Identifiable Assets Acquired and Liabilities Assumed (Parenthetical) (Detail) (Ultrasonix, USD $) In Millions, unless otherwise specified	1 Months Ended
	Mar. 02, 2013
Business Acquisition [Line Items]
Gross amounts due under contracts	$ 8.7
Contract receivable expected uncollectible	2.2
Developed Technology
Business Acquisition [Line Items]
Weighted average useful life	10 years
Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life	10 years 7 months 6 days
Trade Names
Business Acquisition [Line Items]
Weighted average useful life	2 years
Inventories
Business Acquisition [Line Items]
Assets fair value adjustments	3.7
Deferred Revenue
Business Acquisition [Line Items]
Assets fair value adjustments	$ 0.8
Amortization period	4 years 6 months