Collaborative Research Agreements - Additional Information (Detail) - USD ($)		12 Months Ended
	Oct. 14, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2010	Oct. 26, 2015	May. 06, 2013
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements		$ 14,000,000	$ 0	$ 10,000,000
Expenses in research and development		0	0	$ 0
Deferred revenue		55,616,000	41,616,000
Novartis Agreement [Member]
Indefinite-lived Intangible Assets [Line Items]
Deferred revenue		13,000,000	13,000,000
GLP-1 License Agreement [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements		2,000,000
Deferred revenue		32,600,000	23,600,000				$ 10,000,000
Sales and development excess amount		60,000,000
Payment released to Emisphere by milestone		2,000,000
Initial upfront payment		10,000,000
Non-refundable license fee		10,000,000
Payment in support services		1,600,000
GLP-1 License Agreement [Member] | Novo Nordisk [Member]
Indefinite-lived Intangible Assets [Line Items]
Deferred revenue						$ 9,000,000
Expansion License Agreement [Member]
Indefinite-lived Intangible Assets [Line Items]
License agreement termination period	90 days
Expansion License Agreement [Member] | Up-front Payment Arrangement [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements	$ 5,000,000
Expansion License Agreement [Member] | Development and Sales of Exclusively Licensed Molecule Class[Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements	62,500,000
Expansion License Agreement [Member] | Development of Non Exclusively Licensed Molecule Class [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements	20,000,000
Expansion License Agreement [Member] | Development and Sales of Additional Exclusively Licensed Molecule Class [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements	62,500,000
Expansion License Agreement [Member] | Development of Additional Non Exclusively Licensed Molecule Class [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone and upfront payments to agreements	$ 20,000,000
Expansion License Agreement [Member] | Novo Nordisk [Member]
Indefinite-lived Intangible Assets [Line Items]
Deferred revenue		5,000,000
Insulins License Agreement [Member]
Indefinite-lived Intangible Assets [Line Items]
Deferred revenue		$ 5,000,000	$ 5,000,000
Sales and development excess amount					$ 57,500,000
Initial upfront payment					5,000,000
Non-refundable license fee					$ 5,000,000