Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2016	Nov. 29, 2016	Dec. 31, 2015	Dec. 31, 2014
Components Of Income Taxes [Line Items]
Deferred tax assets	$ 856,000	$ 995,000
Valuation allowance for deferred tax assets	145,753,000	131,858,000
Net operating loss carryforwards	267,200,000
Reserve for uncertain tax positions	7,777,000	7,660,000			$ 7,278,000	$ 5,557,000
Unrecognized tax benefits available to offset uncertain tax position liabilities	7,360,000	7,279,000			6,936,000
Net unrecognized benefits	417,000	$ 381,000			$ 342,000
U.S., Canada and Switzerland
Components Of Income Taxes [Line Items]
Valuation allowance for deferred tax assets	145,800,000
U.S., Canada and Switzerland | Net Operating Loss and Research Tax Credit Carryforward
Components Of Income Taxes [Line Items]
Increase in valuation allowance for deferred tax assets	13,900,000
Federal | Canada
Components Of Income Taxes [Line Items]
Net operating loss carryforwards	176,900,000
Capital loss carryforwards	289,500,000
Federal | Canada | Research and Development
Components Of Income Taxes [Line Items]
Net operating loss carryforwards	13,500,000
Scientific, research and experimental development pool	11,400,000
Foreign | U.S.
Components Of Income Taxes [Line Items]
Net operating loss carryforwards	60,500,000
Current income tax expense recorded as result of change in federal tax rate	21,500,000
Reduction in deferred tax assets valuation allowance recorded as result of change in federal tax rate	21,500,000
Incremental U.S. tax for unremitted earnings in foreign subsidiaries	0
Tax liability recorded for unremitted earnings in foreign subsidiaries	0
Foreign | Switzerland
Components Of Income Taxes [Line Items]
Net operating loss carryforwards	29,800,000
State and Local | U.S.
Components Of Income Taxes [Line Items]
Net operating loss carryforwards	$ 39,300,000
Federal and State | U.S. | Foreign Subsidiary | Aegerion
Components Of Income Taxes [Line Items]
Operating loss carryforwards subject to expiration			$ 47,200,000	$ 13,300,000