11. Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Significant Noncash Transactions [Line Items]
Net Income (Loss) Attributable to Parent	$ (20,600)	$ 18,400	$ 18,000	$ 12,300	$ 49,500	$ 17,400	$ 28,400	$ 17,800	$ 28,125	$ 113,093	$ 88,845
Depreciation and amortization									142,900	131,800	149,900
Share-based compensation									19,700	17,000	14,900
(Gain) loss on disposition of securities									(200)	(1,000)	300
Loss on disposition of fixed assets									600	300	400
Excess tax benefits from share-based compensation									(1,506)	(3,610)	(1,349)
Changes in fair value of contingent consideration									(400)	(5,600)	(1,400)
Decrease (increase) in accounts receivable, net									12,500	(39,000)	11,100
(Increase) decrease in inventories, net									(57,100)	(54,200)	5,800
(Increase) decrease in Other Current Assets									(6,600)	100	(5,700)
Increase (decrease) in accounts payable and other current liabilities									30,100	28,600	(9,900)
Increase in Income Taxes Payable									10,700	12,700	20,400
Decrease in deferred income taxes									(51,400)	(6,400)	(6,300)
Other									5,700	4,300	4,000
Decrease in other long term assets									12,700	300	3,600
Increase (Decrease) in Other Long Term Liabilities									8,300	(12,200)	(1,300)
Impairment losses on goodwill and long-lived assets									62,305	0	0
Net cash provided by operating activities									216,433	186,210	273,312
Noncash purchased intangible assets									0	0	200
Noncash Purchased Marketable Securities and Investments									$ 600	$ 2,200	$ 0