CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net earnings	$ 109,946	$ 176,898
Adjustments to reconcile net earnings to net cash provided by operations:
Depreciation and amortization	148,427	142,350
Provision for deferred income taxes	46,264	19,722
Amortization of unearned share-based compensation	8,841	8,378
Amortization of major maintenance costs	14,210	17,160
Amortization of debt issuance costs	600	1,176
Other	(1,090)	844
Increase in cash flows resulting from changes in operating assets and liabilities, net	9,295	10,941
Net cash provided by operating activities	336,493	377,469
Cash flows from investing activities:
Capital expenditures	(169,305)	(265,202)
Acquisitions of businesses and marine equipment	(125,632)	(41,250)
Proceeds from disposition of assets	15,136	13,102
Net cash used in investing activities	(279,801)	(293,350)
Cash flows from financing activities:
Borrowings (payments) on bank credit facilities, net	(49,445)	192,398
Payments on long-term debt	0	(100,000)
Proceeds from exercise of stock options	321	3,712
Purchase of treasury stock	(1,827)	(202,155)
Acquisition of noncontrolling interest	(4,160)	0
Excess tax benefit from equity compensation plans	0	1,015
Other	(2,085)	(873)
Net cash used in financing activities	(57,196)	(105,903)
Decrease in cash and cash equivalents	(504)	(21,784)
Cash and cash equivalents, beginning of year	5,885	24,299
Cash and cash equivalents, end of period	5,381	2,515
Supplemental disclosures of cash flow information:
Interest paid	18,930	19,476
Income taxes paid	14,901	68,952
Capital expenditures included in accounts payable	(2,296)	0
Fair value of property transferred in acquisition	$ 3,681	$ 0