CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES:
Net income	$ 234,497	$ 199,433
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on sale of business	0	4,867
Change in fair value of contingent consideration	(307)	591
Stock compensation expense	12,088	12,346
Excess tax benefit of stock options exercised	(12,354)	(20,994)
Depreciation	45,229	39,514
Amortization	19,884	15,675
Deferred income taxes	15,623	25,462
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Accounts receivable	(43,816)	(4,657)
Accounts payable	2,647	7,246
Accrued liabilities	21,322	(14,945)
Deferred revenues	(614)	615
Other assets and liabilities	41,084	11,994
Net cash provided by operating activities	335,283	277,147
INVESTING ACTIVITIES:
Payments for acquisitions, net of cash acquired	(131,902)	(148,073)
Proceeds from/ (purchase of) short-term investments	45	(49)
Proceeds from sale of business and other assets	0	764
Capital expenditures	(54,329)	(51,658)
Net cash used in investing activities	(186,186)	(199,016)
FINANCING ACTIVITIES:
Repayment of long-term debt and other obligations	(48,858)	(70,630)
Borrowings on foreign bank debt	164,669	74,350
Repayments on foreign bank debt	(163,941)	(47,636)
Borrowings on senior credit facility	731,015	532,701
Repayments on senior credit facility	(725,940)	(629,302)
Payments of deferred financing costs	0	(148)
Payments on capital lease obligations	(2,623)	(2,559)
Purchase and cancellation of treasury stock	(114,531)	(2,945)
Payments to noncontrolling interests	(1,018)	(5,317)
Payments of dividends to noncontrolling interests	0	(398)
Proceeds from issuance of common stock	33,827	44,879
Excess tax benefit of stock options exercised	12,354	20,994
Net cash used in financing activities	(115,046)	(86,011)
Effect of exchange rate changes on cash and cash equivalents	(1,795)	1,574
Net increase/ (decrease) in cash and cash equivalents	32,256	(6,306)
Cash and cash equivalents at beginning of period	31,324	22,511
Cash and cash equivalents at end of period	63,580	16,205
NON-CASH ACTIVITIES:
Net issuance of obligations for acquisitions	88,530	56,361
Net issuance of obligations for noncontrolling interest	$ 2,113	$ 5,901