CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
OPERATING ACTIVITIES:
Net income	$ 136,706	$ 162,447
Adjustments to reconcile net income to net cash provided by operating activities:
Stock compensation expense	10,904	9,124
Excess tax benefit of stock options exercised	(10,899)	(7,080)
Depreciation	37,225	35,120
Amortization	17,718	15,717
Deferred income taxes	973	8,929
Change in fair value of contingent consideration	(640)	3,953
Other, net	6,326	0
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable	(51,041)	(9,606)
Accounts payable	21,019	10,646
Accrued liabilities	22,571	(6,809)
Deferred revenues	(3,156)	2,332
Other assets and liabilities	(9,046)	13,575
Net cash provided by operating activities	178,660	238,348
INVESTING ACTIVITIES:
Payments for acquisitions, net of cash acquired	(61,766)	(304,832)
Proceeds from/ (purchases of) investments	271	(2,052)
Capital expenditures	(46,794)	(43,668)
Net cash used in investing activities	(108,289)	(350,552)
FINANCING ACTIVITIES:
Repayments of long-term debt and other obligations	(39,590)	(28,005)
Borrowings on foreign bank debt	18,363	96,828
Repayments on foreign bank debt	(43,769)	(85,192)
Borrowings on term loan	250,000	0
Borrowings on senior credit facility	879,024	933,101
Repayments on senior credit facility	(1,072,468)	(732,059)
Payments on capital lease obligations	(1,951)	(1,993)
Payments of deferred financing costs	0	(2,280)
Payment for cash flow hedge	(8,833)	0
Purchases and cancellations of treasury stock	(85,149)	(137,186)
Proceeds from issuance of common stock	39,208	21,195
Excess tax benefit of stock options exercised	10,899	7,080
Payments to noncontrolling interests	(2,603)	(732)
Net cash (used in) / provided by financing activities	(56,869)	70,757
Effect of exchange rate changes on cash and cash equivalents	(2,782)	(394)
Net increase/ (decrease) in cash and cash equivalents	10,720	(41,841)
Cash and cash equivalents at beginning of period	22,236	67,167
Cash and cash equivalents at end of period	32,956	25,326
NON-CASH ACTIVITIES:
Issuances of obligations for acquisitions	$ 47,827	$ 83,864