Description of Business, Basis of Presentation and Consolidation and Significant Accounting Policies - Subsidiaries (Details)	Jun. 30, 2018
BeiGene (Hong Kong) Co., Limited.(“BeiGene HK”)
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene (Beijing) Co., Ltd. ("BeiGene (Beijing)")
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene AUS PTY LTD.
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene 101
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene (Suzhou) Co., Ltd. (“BeiGene (Suzhou)”)
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene USA, Inc.(“BeiGene (USA)”)
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene Biologics Co., Ltd. (“BeiGene Biologics”)
Organization
Percentage of Ownership by the Company (as a percent)	95.00%
BeiGene (Shanghai) Co., Ltd. (“BeiGene (Shanghai)”)
Organization
Percentage of Ownership by the Company (as a percent)	95.00%
BeiGene Guangzhou Biologics Manufacturing Co., Ltd. (“BeiGene Guangzhou Factory”)
Organization
Percentage of Ownership by the Company (as a percent)	95.00%
BeiGene (Guangzhou) Co Ltd.
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene Pharmaceutical (Shanghai) Co., Ltd. ("BeiGene Pharmaceutical (Shanghai)")
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene Switzerland
Organization
Percentage of Ownership by the Company (as a percent)	100.00%
BeiGene Ireland
Organization
Percentage of Ownership by the Company (as a percent)	100.00%