Segment Reporting - Operating Results and Reconciliation of Segment Profit to Loss from Operations (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 21,283	$ 16,480	$ 22,973	$ 17,800	$ 11,730
Cost of revenue	(10,188)	(9,076)	(12,361)	(9,777)	(9,128)
Selling, general, and administrative expenses	20,822	10,588	15,486	9,529	8,027
Research and development expenses	(10,469)	(8,253)	(11,635)	(8,990)	(7,547)
Loss from operations	(20,196)	(11,437)	(16,509)	(10,496)	(12,972)
Diagnostics segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Loss from operations	(3,464)	(1,486)	(2,378)
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Loss from operations	9,421	9,820	13,420	12,496	6,924
Operating Segments [Member] \| Life sciences segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	20,754	16,480	22,973	17,800	11,730
Selling, general, and administrative expenses	7,869	5,174	7,175	5,304	4,806
Loss from operations	12,885	11,306	15,798	12,496	6,924
Operating Segments [Member] \| Diagnostics segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	529
Selling, general, and administrative expenses	3,993	1,486	2,378
Operating Segments [Member] \| Service revenue [Member] \| Life sciences segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	1,148	893	1,151	691	224
Operating Segments [Member] \| Instruments [Member] \| Diagnostics segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	488
Operating Segments [Member] \| Instruments [Member] \| Product revenue [Member] \| Life sciences segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	7,226	6,262	8,786	7,112	6,472
Operating Segments [Member] \| Consumables [Member] \| Diagnostics segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	41
Operating Segments [Member] \| Consumables [Member] \| Product revenue [Member] \| Life sciences segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	12,380	9,325	13,036	9,997	5,034
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost of revenue	(10,188)	(9,076)	(12,361)	(9,777)	(9,128)
Research and development expenses	(10,469)	(8,253)	(11,635)	(8,990)	(7,547)
Unallocated selling, general and administrative expenses	$ (8,960)	$ (3,928)	$ (5,933)	$ (4,225)	$ (3,221)

The aggregate cost of goods produced and sold and services rendered during the reporting period.

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

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- Definition

Other generally recurring costs associated with normal operations excluding those directly related to the marketing or selling of products and services not otherwise defined.

+ References

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- Definition

The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 730

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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- Definition

The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.4)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 4

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 330

-SubTopic 10

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6386349&loc=d3e3636-108311

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