Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ 81,586	$ 15,539
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,757	12,715
Stock-based compensation	8,751	11,509
Provision for excess and obsolete inventory	8,707	16,554
Provision for bad debt	450	1,061
Deferred income taxes	474	3,623
Excess tax benefits from stock-based compensation	(416)	(825)
Other	24	173
Changes in operating assets and liabilities:
Trade accounts receivable	9,252	(17,702)
Inventories	(14,476)	(17,949)
Income taxes	(26,765)	3,887
Other current assets	(3,064)	(2,974)
Accrued compensation	(14,079)	6,649
Other current and non-current liabilities	9,904	(737)
Accounts payable	(9,168)	10,468
Other assets	1,763	(209)
Net cash provided by operating activities	67,700	41,782
Cash flows from investing activities:
Acquisition of businesses, net of cash acquired	(86,950)	(2,326)
Purchases of investments	(307,355)	(374,998)
Maturities of investments	211,385	253,231
Sales of investments	182,011	90,580
Proceeds from sale of property, plant and equipment	1,508
Purchases of property, plant and equipment	(9,362)	(9,154)
Other	53	(59)
Net cash used in investing activities	(8,710)	(42,726)
Cash flows from financing activities:
Proceeds from short-term borrowings		6
Payments on short-term borrowings		(776)
Repurchase of common stock	(20,809)	(2,875)
Net receipts (payments) related to employee stock awards	457	(2,464)
Dividend payments to common stockholders	(26,081)	(25,458)
Excess tax benefits from stock-based compensation	416	825
Net cash used in financing activities	(46,017)	(30,742)
Effect of exchange rate changes on cash and cash equivalents	(6,419)	(1,124)
Increase (decrease) in cash and cash equivalents	6,554	(32,810)
Cash and cash equivalents at beginning of period	288,902	287,588
Cash and cash equivalents at end of period	$ 295,456	$ 254,778