Goodwill - Additional Information (Detail)	3 Months Ended
Mar. 31, 2014 Segment
Goodwill [Line Items]
Number of reporting segments	2
Percentage of discount derived from capital asset pricing model	25.00%
Detection [Member]
Goodwill [Line Items]
Percentage of fair value of each reporting unit	362.00%
Therapy [Member]
Goodwill [Line Items]
Percentage of fair value of each reporting unit	179.00%

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration