Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets (liabilities)
Deferred revenue	$ 22,900,000	$ 21,100,000
Warranty reserves	4,600,000	4,600,000
Inventory reserves	7,600,000	7,600,000
Allowance for doubtful accounts	3,300,000	2,500,000
Employee benefits	29,800,000	27,600,000
Foreign loss carryforwards	4,400,000	5,100,000
Federal tax credit carryovers	2,400,000	0
Deferred state tax attributes	8,300,000	11,900,000
Lease liabilities	16,300,000	0
Other, net	5,000,000.0	0
Gross deferred assets	104,600,000	80,400,000
Valuation allowances	(5,300,000)	(1,300,000)
Deferred tax assets after valuation allowances	99,300,000	79,100,000
Undistributed foreign earnings	(13,600,000)	(11,000,000.0)
Property, plant and equipment	(55,800,000)	(47,200,000)
Intangibles	(219,000,000.0)	(172,500,000)
Right of use assets	(15,000,000.0)	0
Other, net	0	(400,000)
Gross deferred liabilities	(303,400,000)	(231,100,000)
Net deferred tax liabilities	(204,100,000)	$ (152,000,000.0)
Deferred tax assets, federal NOL	0
Deferred tax asset for state tax loss carry forwards	5,200,000
Valuation allowance on state tax losses	900,000
Valuation allowance on foreign tax losses	2,000,000.0
Accrual related to foreign withholding taxes	$ 13,600,000