Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net earnings	$ 151,416	$ 155,773
Adjustments to reconcile net earnings to cash flows from operating activities:
Depreciation and amortization of property, plant and equipment	9,702	9,880
Amortization of intangible assets	49,549	38,428
Amortization of deferred financing costs	1,359	1,001
Non-cash stock compensation	18,979	13,801
Changes in operating assets and liabilities, net of acquired businesses:
Accounts receivable	(16,355)	20,304
Unbilled receivables	2,296	(11,042)
Inventories	(3,907)	(7,680)
Accounts payable and accrued liabilities	(19,731)	8,705
Income taxes payable	20,127	38,837
Other, net	(6,363)	(7,608)
Cash provided by operating activities	207,072	260,399
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	(265,248)	(589,577)
Capital expenditures	(9,489)	(9,950)
Proceeds from sale of assets	673	140
Other, net	108	(3,736)
Cash used in investing activities	(273,956)	(603,123)
Cash flows from financing activities:
Proceeds from (Repayments of) revolving line of credit, net	(160,000)	415,000
Principal payments on senior notes	0	0
Principal payments on convertible notes	(289)	(3,454)
Cash premiums paid on convertible note conversions	(915)	(11,236)
Debt issuance costs	(63)	0
Cash dividends to stockholders	(30,173)	(25,024)
Proceeds from stock based compensation, net	690	6,267
Stock award tax excess windfall benefit	0	4,093
Treasury stock sales	879	787
Other	(311)	(289)
Cash provided by/(used in) financing activities	(190,182)	386,144
Effect of foreign currency exchange rate changes on cash	1,588	(38,357)
Net increase/(decrease) in cash and cash equivalents	(255,478)	5,063
Cash and cash equivalents, beginning of period	778,511	610,430
Cash and cash equivalents, end of period	$ 523,033	$ 615,493