CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net earnings	$ 140,047	$ 103,409
Adjustments to reconcile net earnings to net cash provided by operations:
Depreciation and amortization	164,771	167,640
Provision for deferred income taxes	40,502	36,838
Amortization of unearned share-based compensation	11,079	16,649
Amortization of leases	(410)	0
Amortization of major maintenance costs	17,295	15,600
Amortization of debt issuance costs	1,212	898
Other	(5,875)	(2,023)
Increase (decrease) in cash flows resulting from changes in operating assets and liabilities, net	18,978	(66,707)
Net cash provided by operating activities	387,599	272,304
Cash flows from investing activities:
Capital expenditures	(184,068)	(231,752)
Acquisitions of businesses and marine equipment, net of cash acquired	(257,540)	(499,227)
Proceeds from disposition of assets	34,490	27,806
Net cash used in investing activities	(407,118)	(703,173)
Cash flows from financing activities:
Payments on bank credit facilities	(417,377)	(88,392)
Borrowings on long-term debt	500,000	499,295
Payments on long-term debt	(60,000)	0
Payments of debt issue costs	(2,397)	(4,276)
Proceeds from exercise of stock options	3,563	13,264
Payments related to tax withholding for share-based compensation	(2,031)	(4,821)
Other	(614)	(686)
Net cash provided by financing activities	21,144	414,384
Increase (decrease) in cash and cash equivalents	1,625	(16,485)
Cash and cash equivalents, beginning of year	7,800	20,102
Cash and cash equivalents, end of period	9,425	3,617
Cash paid during the period:
Interest paid	52,436	37,175
Income taxes paid	3,155	495
Operating cash outflow from operating leases	29,424	0
Non-cash investing activity:
Capital expenditures included in accounts payable	6,410	(5,554)
Cash acquired in acquisition	0	2,313
Right-of-use assets obtained in exchange for lease obligations	$ 9,736	$ 0