Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2017
Difference between the effective income tax provision rate and the U.S. federal statutory income tax provision rate
U.S. federal statutory income tax rate (as a percent)	35.00%	35.00%	35.00%
U.S. state income taxes, net of federal income tax benefit (as a percent)	1.90%	1.90%	2.10%
Tax on foreign dividends	(0.30%)
Tax on foreign dividends (as a percent)		4.50%	3.60%
Foreign tax rate differences (as a percent)	(3.40%)	(2.70%)	(2.20%)
Foreign financing structure (as a percent)	(2.20%)	(1.60%)	(1.30%)
Excess tax benefits from stock compensation (as a percent)	(4.90%)	(3.00%)	(0.00%)
Research and development and other tax credits (as a percent)	(3.30%)	(2.80%)	(3.90%)
Domestic production activities deduction (as a percent)	(0.60%)	(1.50%)	(2.20%)
Uncertain income tax positions (as a percent)	0.80%	(0.40%)	1.30%
Change in statutory rates (as a percent)	(10.60%)	0.00%	0.00%
Other differences - net (as a percent)	0.00%	(0.70%)	0.30%
Effective income tax rate (as a percent)	12.40%	28.70%	32.70%
Difference between the effective income tax provision and the U.S. federal statutory income tax provision
U.S. federal statutory income tax rate	$ 32.1	$ 36.1	$ 31.5
U.S. state income taxes, net of federal income tax benefit	1.7	2.0	1.9
Effective income tax rate reconciliation, repatriation of foreign earnings, transition tax for accumulated foreign earnings, amount	(0.3)
Tax on foreign dividends		4.6	3.2
Foreign tax rate differences	(3.1)	(2.8)	(2.0)
Benefit of tax structure	(2.0)	(1.7)	(1.2)
Excess tax benefits from stock compensation	(4.5)	(3.1)	0.0
Research and development and other credits	(3.0)	(2.9)	(3.5)
Domestic production activities deduction	(0.5)	(1.5)	(2.0)
Uncertain tax positions	0.7	(0.4)	1.2
Change in statutory tax rate, amount	(9.7)	0.0	0.0
Other differences - net	0.0	(0.7)	0.3
Total provision for income taxes	11.4	29.6	29.4
Undistributed foreign earnings	0.0	$ (4.4)
FiberMark
Difference between the effective income tax provision and the U.S. federal statutory income tax provision
Research and development and other credits			$ (1.4)
Federal Ministry of Finance, Germany
Difference between the effective income tax provision and the U.S. federal statutory income tax provision
Change in statutory tax rate, amount	$ 0.6
Undistributed foreign earnings				$ 4.1