Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities:
Consolidated net income	$ 66,124	$ 8,961	$ 84,459
Depreciation	88,195	90,577	71,780
Amortization of acquired intangible assets	382,416	404,475	231,590
Amortization of deferred financing fees and debt discount	7,960	7,705	9,646
Deferred income taxes	(74,465)	(148,418)	5,418
Foreign currency remeasurement of deferred taxes	9,360	(16,356)
Stock-based compensation expense	81,557	60,049	64,218
Impairment of goodwill and intangible assets	55,000	2,200
Provision for non-cash warrants		30,159
Provision (recovery) for doubtful accounts	(566)	1,386	2,997
Loss on disposal of property, plant & equipment and other	7,063	8,706	7,776
Loss on investments and other	11,066	21,194	6,220
Excess income tax benefits from stock-based compensation plans		(20,085)	(3,997)
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	175,930	(258,677)	(55,132)
Other receivables	(84,652)	(31,517)	(6,017)
Inventories	(224,582)	282,644	(6,685)
Accounts payable and accrued liabilities	49,988	(178,086)	15,065
Prepaids and other, net	(16,557)	97,578	(83,466)
Net cash provided by operating activities	533,837	362,495	343,872
Investing activities:
Purchases of investments	(68,493)	(141,543)	(48,566)
Sales of investments	165,301	25,931	161,824
Purchases of property, plant and equipment	(78,072)	(66,760)	(49,890)
Purchases of intangible assets	(6,422)	(5,526)	(39,340)
Proceeds from sale-leaseback transaction			24,960
Acquisition, net of cash acquired	(760,802)	(340,118)	(97,905)
Other, net	826	3,507	2,971
Net cash used in investing activities	(747,662)	(524,509)	(45,946)
Financing activities:
Proceeds from issuance of shares, net	17,469	12,885	16,189
Repurchase of shares	(196,965)	(178,035)	(24,999)
Excess income tax benefits from stock-based compensation plans		20,085	3,997
Repurchase of shares to satisfy employee minimum tax withholdings	(26,573)	(17,925)	(46,680)
Proceeds from issuance of debt	175,847	800,000
Payment of debt obligations	(244,009)	(319,750)	(53,500)
Payment of financing lease obligation	(777)	(758)	(425)
Proceeds from sale-leaseback financing transaction			58,729
Payment for account receivable financing facility		(23,546)
Payment for deferred financing fees and debt discount	(5,961)	(2,304)	(8,239)
Contribution from noncontrolling interest	3,500		54,794
Net cash (used in) provided by financing activities	(277,469)	290,652	(134)
Effect of exchange rate changes on cash and cash equivalents	(1,256)	(12,097)
Net (decrease) increase in cash and cash equivalents	(492,550)	116,541	297,792
Cash and cash equivalents at beginning of year	980,123	863,582	565,790
Cash and cash equivalents at end of year	487,573	980,123	863,582
Supplemental cash flow information:
Interest paid during the year	80,791	71,127	60,798
Income taxes paid during the year	$ 34,053	111,524	39,065
Non-cash investing and financing activities: debt assumed in acquisition		$ 263,795	$ 15,000