CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net earnings	$ 44,457	$ 32,666
Adjustments to reconcile net earnings to net cash provided by operations:
Depreciation and amortization	55,223	54,218
Provision for deferred income taxes	12,490	8,846
Amortization of unearned share-based compensation	4,900	7,551
Amortization of leases	446	0
Amortization of major maintenance costs	4,974	4,893
Amortization of debt issuance costs	320	259
Other	(2,544)	(1,773)
Decrease in cash flows resulting from changes in operating assets and liabilities, net	(81,737)	(87,926)
Net cash provided by operating activities	38,529	18,734
Cash flows from investing activities:
Capital expenditures	(60,932)	(40,961)
Acquisitions of businesses and marine equipment, net of cash acquired	(247,470)	(429,977)
Proceeds from disposition of assets	13,187	12,181
Net cash used in investing activities	(295,215)	(458,757)
Cash flows from financing activities:
Payments on bank credit facilities	(240,801)	(64,414)
Borrowings on long-term debt	500,000	499,295
Payments of debt issue costs	(2,232)	(4,251)
Proceeds from exercise of stock options	1,415	292
Payments related to tax withholding for share-based compensation	(2,003)	(3,766)
Other	(204)	(225)
Net cash provided by financing activities	256,175	426,931
Decrease in cash and cash equivalents	(511)	(13,092)
Cash and cash equivalents, beginning of year	7,800	20,102
Cash and cash equivalents, end of period	7,289	7,010
Cash paid (received) during the period:
Interest paid	23,257	10,763
Income taxes refunded	(1,024)	(721)
Operating cash outflow from operating leases	10,142	0
Capital expenditures included in accounts payable	(5,022)	(5,448)
Non-cash investing activity:
Cash acquired in acquisition	0	2,313
Right-of-use assets obtained in exchange for lease obligations	$ 1,292	$ 0