Income Taxes - Components of Deferred Income Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating losses	$ 323.0	$ 355.7
Tax credits	62.0	49.2
Interest carryforward	44.4	34.2
Employee benefits	40.3	56.2
Accrued liabilities	25.9	50.6
Financing activities	24.3	3.5
Goodwill	19.5	31.4
Accounts receivable	19.1	19.8
Research and development costs	10.3	15.2
Inventory	4.6	8.5
Other	20.7	24.1
Total deferred tax assets	594.1	648.4
Valuation allowance	(391.7)	(383.3)
Total gross deferred tax assets	202.4	265.1
Deferred tax liabilities:
Intangibles	710.4	831.9
Plant and equipment	24.8	33.9
Undistributed foreign earnings	21.9	36.8
Other	0.4	6.9
Total gross deferred tax liabilities	757.5	909.5
Net deferred tax liability	$ 555.1	$ 644.4