Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Earnings from continuing operations before income taxes [Abstract]
United States	$ 88,301,000	$ 76,025,000	$ 50,278,000
Foreign	37,654,000	29,444,000	17,167,000
Earnings from continuing operations before income tax provision	125,955,000	105,469,000	67,445,000
Current [Abstract]
U.S. federal and state income taxes	35,054,000	21,466,000	15,815,000
Foreign	12,324,000	8,465,000	6,663,000
Total current	47,378,000	29,931,000	22,478,000
Deferred [Abstract]
U.S. federal and state income taxes	1,885,000	9,820,000	2,819,000
Foreign, deferred	(5,165,000)	(254,000)	(1,383,000)
Total deferred	(3,280,000)	9,566,000	1,436,000
Total provision for taxes	44,098,000	39,498,000	23,914,000
Cash payments for income taxes [Abstract]
Cash payments for income taxes	44,100,000	30,500,000	18,800,000
Reconciliation of the income tax provision from statutory to GAAP [Abstract]
Tax provision computed at statutory rate	44,084,000	36,914,000	23,606,000
Tax effect of [Abstract]
Expenses for which no benefit was realized	492,000	702,000	202,000
Change in effective state tax rate	23,000	(6,000)	13,000
Tax credit	(239,000)	(733,000)	(930,000)
State taxes net of federal benefit	2,512,000	1,779,000	1,813,000
Benefit of manufacturing deduction	(3,093,000)	(1,492,000)	(1,127,000)
Acquisition costs	2,437,000	1,919,000	0
Foreign operations	(1,217,000)	520,000	530,000
Other, net	(901,000)	(105,000)	(193,000)
Total provision for taxes	44,098,000	39,498,000	23,914,000
Estimated tax benefit	678,000
Deferred income tax assets [Abstract]
Pension costs	43,788,000	36,430,000
Payroll and benefits	1,129,000	1,365,000
Accrued warranty expenses	1,906,000	1,425,000
Postretirement benefits	9,137,000	8,143,000
Accrued liabilities	261,000	591,000
Other, net	8,573,000	1,680,000
Total deferred income tax assets, gross	64,794,000	49,634,000
Less valuation allowance	(4,779,000)	(1,117,000)
Total deferred income tax assets, net	60,015,000	48,517,000
Noncurrent deferred income tax liabilities [Abstract]
Prepaid expenses	(792,000)	(993,000)
Depreciation	(33,781,000)	(34,143,000)
Inventories	(974,000)	(1,758,000)
Liability for unremitted earnings	(12,005,000)	0
Intangible assets	(17,527,000)	(8,784,000)
Other, net	(210,000)	(5,585,000)
Total noncurrent deferred income tax liabilities, net	(65,289,000)	(51,263,000)
Total net deferred tax liability	(5,274,000)	(2,746,000)
Current deferred tax asset	574,000	1,140,000
Non-current deferred tax liability	(5,848,000)	(3,886,000)
Total net deferred tax liability	(5,274,000)	(2,746,000)
Unrecognized tax benefits [Abstract]
Unrecognized tax benefits that would affect the net effective income tax rate in any future period	3,000,000	2,100,000	1,800,000
Reconciliation of unrecognized tax benefits [Roll Forward]
Balance, beginning of period	2,060,000	1,838,000	1,509,000
Gross increases - current year tax positions	4,255,000	791,000	372,000
Gross increases - tax positions from prior periods	3,000	115,000	233,000
Gross decreases - tax positions from prior periods	(683,000)	(657,000)	(262,000)
Settlements	0	(27,000)	(14,000)
Balance, end of period	5,635,000	2,060,000	1,838,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Company entered into an agreement whereby the former owners funded an escrow account	5,500,000
Interest and penalties accrued [Abstract]
Accrual for interest and penalties	100,000
Unrecognized tax benefits, income tax penalties and interest expense	10,000	45,000	30,000
Tax credits and other various deductions [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Estimated change in unrecognized tax benefits expected within the next twelve months	1,900,000
Undistributed Earnings of Foreign Subsidiaries that the Company Intends to Permanently Reinvest [Member]
Deferred Tax Liability Not Recognized [Line Items]
Cumulative amount on which no deferred U.S. income taxes have been provided	$ 115,500,000