Fair Value Measurement of Assets and Liabilities - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Liabilities:
Contingent considerations	$ 4,833,061
Fair Value, Measurements, Recurring [Member]
Assets
Total Financial Assets	346,098,553	75,354,552
Liabilities:
Contingent considerations	4,833,061
Total Financial Liabilities	4,833,061
Fair Value, Measurements, Recurring [Member] \| Money Market Funds [Member]
Assets
Cash and Cash Equivalents	37,495,186	19,630,109
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member]
Assets
Cash and Cash Equivalents	13,003,843	88,648
Investments	238,643,291	25,239,905
Fair Value, Measurements, Recurring [Member] \| Sovereign Debt Securities [Member]
Assets
Investments	49,149,930	30,395,890
Fair Value, Measurements, Recurring [Member] \| Certificates of Deposit [Member]
Assets
Investments	7,806,303
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for (Level 1) [Member]
Assets
Total Financial Assets	146,672,503	69,225,356
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for (Level 1) [Member] \| Money Market Funds [Member]
Assets
Cash and Cash Equivalents	37,495,186	19,630,109
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for (Level 1) [Member] \| Corporate Debt Securities [Member]
Assets
Cash and Cash Equivalents	108,028	88,648
Investments	59,919,359	19,110,709
Fair Value, Measurements, Recurring [Member] \| Quoted Prices in Active Markets for (Level 1) [Member] \| Sovereign Debt Securities [Member]
Assets
Investments	49,149,930	30,395,890
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Total Financial Assets	199,426,050	6,129,196
Liabilities:
Contingent considerations	4,833,061
Total Financial Liabilities	4,833,061
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Corporate Debt Securities [Member]
Assets
Cash and Cash Equivalents	12,895,815
Investments	178,723,932	6,129,196
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Certificates of Deposit [Member]
Assets
Investments	$ 7,806,303

Total financial assets.

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Fair value of contingent consideration in a business combination that is classified in shareholders' equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

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Fair value of financial and nonfinancial obligations.

+ References

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