Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows - operating activities:
Net income including noncontrolling interests	$ 52,192	$ 61,788
Depreciation and amortization	16,895	14,768
Amortization of identifiable intangible assets	12,687	14,930
Deferred income taxes	(436)	1,479
Excess tax benefits from share-based compensation	(994)	(5,282)
Equity income from unconsolidated entities	(240)	(414)
Other non-cash items	2,062	4,478
Distributions from unconsolidated entities	634	866
Changes in operating assets and liabilities, excluding the effect of businesses acquired	(135,011)	(103,175)
Net cash used in operating activities	(52,211)	(10,562)
Cash flows - investing activities:
Payments for acquisitions of businesses, net of cash acquired, and related contingent consideration arrangement	(1,050)	(20,613)
Proceeds from sale of property, plant and equipment	861	719
Purchase of property, plant and equipment	(14,820)	(19,012)
Purchase of short-term investments	0	(17,782)
Maturity of short-term investments	4,616	17,693
Net cash used in investing activities	(10,393)	(38,995)
Cash flows - financing activities:
Repayments of long-term debt	(4)	(37)
Repayments of capital lease obligations	(786)	(1,310)
Dividends paid to stockholders	(4,027)	(6,660)
Repurchase of common stock	(4,998)	(21,189)
Proceeds from exercise of stock options	1,933	1,909
Payments to satisfy minimum tax withholding	(927)	(733)
Issuance of common stock under employee stock purchase plan	1,344	1,263
Payments for contingent consideration arrangements	(537)	(5,748)
Distributions to noncontrolling interests	(1,050)	(1,000)
Excess tax benefits from share-based compensation	994	5,282
Net cash used in financing activities	(8,058)	(28,223)
Effect of exchange rate changes on cash and cash equivalents	(4,256)	730
Decrease in cash and cash equivalents	(74,918)	(77,050)
Cash and cash equivalents at beginning of year	605,303	511,322
Cash and cash equivalents at end of period	530,385	434,272
Cash paid for:
Interest	2,730	2,545
Income taxes	68,147	47,071
Non-cash financing activities:
Assets acquired under capital lease obligations	352	1,021
Common stock dividends declared	$ 0	$ 3,358