Revenue Revenue (Impact of Adoption of Topic 606) (Details) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net of allowances	$ 325,741	$ 298,440
Inventories	331,969	309,279
Contract assets	32,125	32,348
Prepaid expenses and other current assets	66,818	56,249
Total assets	1,906,101	1,576,111	$ 1,473,350
Accrued expenses and other liabilities	117,825	110,276
Contract liabilities	31,094	34,888
Liabilities	924,589	701,452
Liabilities and Equity	$ 1,906,101	$ 1,576,111