CONSOLIDATED STATEMENTS OF Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 49,527	$ 46,464
Adjustments to reconcile net earnings to net cash used in operating activities:
Depreciation and amortization	14,651	15,112
Deferred income taxes	23	170
Amortization of marketable security premiums	2,221	2,349
Changes in operating assets and liabilities:
Accounts receivable	(31,367)	(55,672)
Other receivables	2,622	(966)
Inventories	(2,826)	(7,804)
Prepaid expenses and other assets	3,678	11,364
Accounts payable and accrued liabilities	6,906	11,136
Income taxes payable	3	8,195
Postretirement health care benefits	(902)	(597)
Deferred compensation and other liabilities	2,496	509
Net cash from operating activities	47,032	30,260
CASH FLOWS FROM INVESTING ACTIVITIES:
Restricted cash		227
Capital expenditures	(13,067)	(12,421)
Purchases of trading securities	(3,064)	(3,333)
Sales of trading securities	645	2,275
Purchase of available for sale securities	(45,298)	(45,826)
Sale and maturity of available for sale securities	26,517	40,390
Net cash used in investing activities	(34,267)	(18,688)
CASH FLOWS FROM FINANCING ACTIVITIES:
Shares purchased and retired	(26,293)	(22,998)
Dividends paid in cash	(16,694)	(15,269)
Proceeds from bank loans	2,156
Repayment of bank loans	(2,339)	(87)
Net cash used in financing activities	(43,170)	(38,354)
Effect of exchange rate changes on cash	(1,501)	(2,600)
Decrease in cash and cash equivalents	(31,906)	(29,382)
Cash and cash equivalents at beginning of year	126,145	100,108
Cash and cash equivalents at end of year	94,239	70,726
Supplemental cash flow information:
Income taxes paid, net	22,622	11,766
Interest paid	19	15
Stock dividend issued	$ 61,671	$ 57,220