Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net earnings	$ 427,247	$ 322,580	$ 239,481
Adjustments to reconcile net earnings to cash flows from operating activities:
Depreciation and amortization of property, plant and equipment	36,780	36,728	34,163
Amortization of intangible assets	103,363	86,293	69,285
Amortization of deferred financing costs	2,362	2,362	2,573
Non-cash stock compensation	31,730	25,150	27,476
Changes in operating assets and liabilities, net of acquired businesses:
Accounts receivable	(33,333)	(9,697)	26,978
Inventories	(23,033)	(5,687)	31,081
Unbilled Receivables	11,759	(16,115)	4,015
Accounts payable and accrued liabilities	24,347	52,540	(58,801)
Income taxes payable	14,526	10,123	(6,225)
Other, net	5,870	(4,737)	(2,527)
Cash provided by operating activities	601,618	499,540	367,499
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	233,594	536,413	354,561
Capital expenditures	40,702	28,591	25,885
Proceeds from sale of assets	1,990	6,068	11,218
Other, net	(3,443)	(4,338)	(4,964)
Cash used in investing activities	(275,749)	(563,274)	(374,192)
Cash flows from financing activities:
Proceeds from senior notes	0	0	500,000
Proceeds from/(payments on) senior unsecured term loan	0	0	(350,000)
Borrowings/(payments) under revolving line of credit, net	(230,000)	190,000	(139,000)
Principal payments on convertible notes	(26,457)	(23,411)	(124,270)
Debt issuance costs	0	0	(4,708)
Cash dividends to stockholders	(42,090)	(35,706)	(29,823)
Treasury stock sales	2,104	1,697	1,693
Stock award tax excess windfall benefit	12,664	6,364	2,813
Proceeds from issuance of common stock, net of issue costs	0	0	121,450
Proceeds from stock option exercises	28,167	29,047	10,506
Other	1,067	382	2,258
Cash provided by/(used in) financing activities	(256,679)	167,609	(13,597)
Effect of exchange rate changes on cash	(1,483)	(1,189)	9,929
Net increase/(decrease) in cash and cash equivalents	67,707	102,686	(10,361)
Cash and cash equivalents, beginning of year	270,394		178,069
Cash and cash equivalents, end of year	338,101	270,394
Cash paid for:
Interest	62,840	64,831	47,867
Income taxes, net of refunds received	150,550	109,327	103,699
Noncash investing activities:
Fair value of assets, including goodwill	256,589	687,017	384,055
Liabilities assumed	(22,995)	(150,604)	(29,494)
Cash paid, net of cash acquired	$ 233,594	$ 536,413	$ 354,561