CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
OPERATING ACTIVITIES:
Net income	$ 199,433	$ 172,220
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on sale of business	4,867	323
Change in fair value of contingent consideration	591	(2,140)
Accelerated amortization of term loan financing fees	0	1,241
Stock compensation expense	12,346	11,563
Excess tax benefit of stock options exercised	(20,994)	(16,614)
Depreciation	39,514	36,885
Amortization	15,675	11,102
Deferred income taxes	25,462	27,685
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Accounts receivable	(4,657)	(20,288)
Accounts payable	7,246	(11,239)
Accrued liabilities	(972)	16,694
Deferred revenues	615	(1,241)
Other assets and liabilities	(1,979)	(11,015)
Net cash provided by operating activities	277,147	215,176
INVESTING ACTIVITIES:
Payments for acquisitions, net of cash acquired	(153,390)	(467,430)
(Purchase of) / proceeds from short-term investments	(49)	15,941
Proceeds from sale of business and other assets	764	2,371
Capital expenditures	(51,658)	(36,981)
Net cash used in investing activities	(204,333)	(486,099)
FINANCING ACTIVITIES:
Repayment of long-term debt and other obligations	(70,630)	(48,768)
Borrowings on foreign bank debt	74,350	39,730
Repayments on foreign bank debt	(47,636)	(8,256)
Borrowings on senior credit facility	532,701	1,433,405
Repayments on senior credit facility	(629,302)	(1,163,613)
Payments of deferred financing costs	(148)	(3,740)
Payments on capital lease obligations	(2,559)	(2,703)
Purchase and cancellation of treasury stock	(2,945)	(81,201)
Payments to noncontrolling interests	(398)	0
Proceeds from other issuance of common stock	44,879	30,487
Excess tax benefit of stock options exercised	20,994	16,614
Net cash (used in)/ provided by financing activities	(80,694)	211,955
Effect of exchange rate changes on cash	1,574	3,087
Net decrease in cash and cash equivalents	(6,306)	(55,881)
Cash and cash equivalents at beginning of period	22,511	79,276
Cash and cash equivalents at end of period	16,205	23,395
NON-CASH ACTIVITIES:
Net issuance of obligations for acquisitions	$ 62,262	$ 41,847