Recent Accounting Pronouncements Level 1 (Notes)	3 Months Ended
Mar. 31, 2019
Recent Accounting Pronouncements [Abstract]
New Accounting Pronouncements, Policy	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842). ASU 2016-02 requires companies that lease assets to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, in its balance sheet. The pronouncement also requires additional disclosures about the amount, timing and uncertainty of cash flows arising from leases. This pronouncement is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. This ASU is required to be adopted using a modified retrospective approach. Management adopted ASU 2016-02 on January 1, 2019 and elected the practical expedient that allows entities to not apply the new guidance in the comparative periods they present in their financial statements in the year of adoption. Consequently, prior year financial information has not been updated and the disclosures required under the new standard has not been provided for periods prior to January 1, 2019. Upon adoption, the Company recognized $2.1 million for right-of-use assets and corresponding liabilities on the consolidated balance sheet, primarily related to lease of office space. The adoption of this ASU on January 1, 2019 did not have a material impact on Lexicon’s consolidated financial statements. Pronouncements Not Yet Adopted. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606. This targeted amendment to Topic 808 clarifies that certain transactions resulting from a collaborative agreement should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer for a good or service that is a distinct unit-of-account. This amendment is effective for fiscal years, and interim periods within years presented, beginning after December 15, 2019, and should be applied retrospectively to the date of initial application of Topic 606. The Company has applied the provisions of Topic 606 to account for its transactions for collaboration arrangements, including recognition, measurement, presentation and disclosure requirement, and does not expect adoption of this ASU to have a material impact on its consolidated financial statements.

Recent Accounting Pronouncements

In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842). ASU 2016-02 requires companies that lease assets to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, in its balance sheet. The pronouncement also requires additional disclosures about the amount, timing and uncertainty of cash flows arising from leases. This pronouncement is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. This ASU is required to be adopted using a modified retrospective approach. Management adopted ASU 2016-02 on January 1, 2019 and elected the practical expedient that allows entities to not apply the new guidance in the comparative periods they present in their financial statements in the year of adoption. Consequently, prior year financial information has not been updated and the disclosures required under the new standard has not been provided for periods prior to January 1, 2019. Upon adoption, the Company recognized $2.1 million for right-of-use assets and corresponding liabilities on the consolidated balance sheet, primarily related to lease of office space. The adoption of this ASU on January 1, 2019 did not have a material impact on Lexicon’s consolidated financial statements.

Pronouncements Not Yet Adopted. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606. This targeted amendment to Topic 808 clarifies that certain transactions resulting from a collaborative agreement should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer for a good or service that is a distinct unit-of-account. This amendment is effective for fiscal years, and interim periods within years presented, beginning after December 15, 2019, and should be applied retrospectively to the date of initial application of Topic 606. The Company has applied the provisions of Topic 606 to account for its transactions for collaboration arrangements, including recognition, measurement, presentation and disclosure requirement, and does not expect adoption of this ASU to have a material impact on its consolidated financial statements.