CONSOLIDATED STATEMENTS OF EARNINGS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue, Net [Abstract]
Product sales	$ 1,815,028	$ 1,719,591	$ 1,450,313
Service sales	428,098	398,490	372,994
Total net sales	2,243,126	2,118,081	1,823,307
Cost of Revenue [Abstract]
Cost of product sales	1,190,714	1,123,291	960,878
Cost of service sales	275,896	258,951	250,010
Total cost of sales	1,466,610	1,382,242	1,210,888
Gross profit	776,516	735,839	612,419
Research and development expenses	(67,842)	(63,580)	(54,352)
Selling expenses	(128,005)	(128,473)	(107,618)
General and administrative expenses	(298,296)	(306,663)	(269,055)
Operating income	282,373	237,123	181,394
Interest expense	(35,794)	(37,053)	(26,301)
Other income, net	365	980	128
Earnings before income taxes	246,944	201,050	155,221
Provision for income taxes	(76,995)	(61,646)	(51,140)
Earnings from continuing operations	169,949	139,404	104,081
Discontinued operations, net of taxes
Gain/(loss) from discontinued operations, net of taxes	(56,611)	(1,423)	9,763
Net earnings	$ 113,338	$ 137,981	$ 113,844
Basic earnings per share
Earnings from continuing operations	$ 3.54	$ 2.97	$ 2.23
Earnings from discontinued operations	$ (1.18)	$ (0.03)	$ 0.21
Total	$ 2.36	$ 2.94	$ 2.44
Diluted earnings per share
Earnings from continuing operations	$ 3.46	$ 2.91	$ 2.20
Earnings from discontinued operations	$ (1.15)	$ (0.03)	$ 0.21
Total	$ 2.31	$ 2.88	$ 2.41
Dividends per share	$ 0.52	$ 0.39	$ 0.35
Weighted average shares outstanding:
Basic	48,019	46,991	46,743
Diluted	49,075	47,912	47,412