Business Combinations - Schedule of Acquisition-Date Fair Value (Detail) (Pregenen [Member], USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2014
Pregenen [Member]
Business Acquisition [Line Items]
Cash	$ 5,093
Common stock	19,348
Contingent consideration	6,550
Total purchase consideration	$ 30,991

Value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of liability recognized arising from contingent consideration in a business combination.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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