CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH PROVIDED BY OPERATING ACTIVITIES:
Net earnings	$ 241,686	$ 200,261	$ 177,015
Income items not affecting cash:
Depreciation and amortization	49,534	57,245	62,796
Deferred income taxes	2,863	(1,242)	(2,709)
Stock-based compensation arrangements	25,748	30,788	27,823
Gain on sale of certain optics assets	(19,166)	(4,129)	0
Other non-cash items	7,722	(791)	4,564
Changes in operating assets and liabilities, net of acquisitions:
(Increase) decrease in accounts receivable,net	28,258	(76,705)	48,640
Decrease (increase) in inventories	(74,816)	11,363	35,181
Decrease (increase) in prepaid expenses and other current assets	1,858	5,754	5,434
(Increase) decrease in other assets	(4,333)	(24,261)	(1,520)
Increase) decrease in accounts payable	38,660	15,040	(8,617)
Increase (decrease) in deferred revenue	3,503	93	(659)
Increase (decrease) in accrued payroll and other liabilities	(20,072)	17,240	36,017
(Decrease) increase in accrued income taxes	(9,319)	(8,501)	(18,898)
Increase (decrease) in pension and other long-term liabilities	3,688	4,089	(10,102)
Cash provided by operating activities	275,814	226,244	354,965
CASH USED BY INVESTING ACTIVITIES:
Additions to property and equipment	(68,234)	(61,262)	(52,061)
Business acquisitions, net of cash acquired	(92,260)	0	(20,073)
Proceeds from sale of certain optics assets	25,649	12,000	0
Cash used by investing activities	(134,845)	(49,262)	(72,134)
CASH (USED) PROVIDED BY FINANCING ACTIVITIES:
Net proceeds of long-term debt, including current portion	0	0	150,000
Repayment of long-term debt	(15,000)	(15,000)	(11,250)
Repurchase of common stock	(123,193)	(139,238)	(162,078)
Dividends paid	(61,399)	(56,513)	(51,404)
Proceeds from shares issued pursuant to stock-based compensation plans	24,835	47,581	8,650
Excess tax benefit of stock options exercised	8,243	11,161	1,069
Other financing activities	(24)	(18)	(1,100)
Cash (used) provided by financing activities	(166,538)	(152,027)	(66,113)
Effect of exchange rate changes on cash	(33,020)	(36,057)	4,019
Net decrease (increase) in cash and cash equivalents	(58,589)	(11,102)	220,737
Cash and cash equivalents, beginning of year	531,374	542,476	321,739
Cash and cash equivalents, end of year	$ 472,785	$ 531,374	$ 542,476