Post Employment Plans - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) years	Dec. 31, 2017 USD ($)	Dec. 31, 2016	Dec. 31, 2013 plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amount to be amortized from accumulated other comprehensive income (loss) next fiscal year	$ 0.7
Expected future benefit payments, year one through five	12.3
Estimated future employer contributions in next fiscal year	2.4
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected future benefit payments, year one through five	$ 1.0
Postretirement health coverage
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Retiree eligible age | years	65
Pension plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on assets, percent	2.94%	2.90%	2.89%
Deferred compensation arrangement with individual, by type of compensation, pension and Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash surrender value of insurance policies	$ 31.5	$ 34.6
Deferred compensation liability, non-current	$ 28.8	$ 31.6
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer nondiscretionary contribution to plan	3.00%
Ireland
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer matching contribution, percent of employees' gross pay	18.00%
Elan corporation
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of defined benefit plans assumed | plan				2