Revenue Revenue (Impact of Adoption of Topic 606) (Details) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowances	$ 298,440		$ 322,892
Inventories, net	309,279		309,060
Contract assets	32,348	$ 38,557	0
Costs in excess of billings on uncompleted contracts	0		28,738
Prepaid expenses and other current assets	56,249		57,949
Total assets	1,576,111		1,473,350	$ 1,395,014
Accrued expenses and other liabilities	110,276		96,262
Contract liabilities	34,888	26,330	0
Billings in excess of costs on uncompleted contracts	0		18,428
Liabilities	701,452		726,451
Liabilities and Equity	1,576,111		$ 1,473,350
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowances		314,008
Inventories, net		305,932
Contract assets		38,557
Costs in excess of billings on uncompleted contracts		0
Prepaid expenses and other current assets		61,077
Total assets		1,474,285
Accrued expenses and other liabilities		89,295
Contract liabilities		26,330
Billings in excess of costs on uncompleted contracts		0
Liabilities		727,386
Liabilities and Equity		1,474,285
Accounting Standards Update 2014-09 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowances	306,600
Inventories, net	312,055
Contract assets	0
Costs in excess of billings on uncompleted contracts	23,769
Prepaid expenses and other current assets	53,473
Total assets	1,575,692
Accrued expenses and other liabilities	120,118
Contract liabilities	0
Billings in excess of costs on uncompleted contracts	24,627
Liabilities	701,033
Liabilities and Equity	1,575,692
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowances	(8,160)	(8,884)
Inventories, net	(2,776)	(3,128)
Contract assets	32,348	38,557
Costs in excess of billings on uncompleted contracts	(23,769)	(28,738)
Prepaid expenses and other current assets	2,776	3,128
Total assets	419	935
Accrued expenses and other liabilities	(9,842)	(6,967)
Contract liabilities	34,888	26,330
Billings in excess of costs on uncompleted contracts	(24,627)	(18,428)
Liabilities	419	935
Liabilities and Equity	$ 419	$ 935