CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net earnings	$ 61,411	$ 63,011
Adjustments to reconcile net earnings to net cash provided by operations:
Depreciation and amortization	45,766	41,036
Provision for deferred income taxes	7,182	8,784
Amortization of unearned share-based compensation	2,538	2,153
Amortization of major maintenance costs	4,932	3,684
Other	(1,124)	(79)
Decrease in cash flows resulting from changes in operating assets and liabilities, net	(18,140)	(3,378)
Net cash provided by operating activities	102,565	115,211
Cash flows from investing activities:
Capital expenditures	(96,533)	(62,257)
Acquisition of marine equipment	(41,250)	0
Proceeds from disposition of assets	10,240	363
Net cash used in investing activities	(127,543)	(61,894)
Cash flows from financing activities:
Borrowings (payments) on bank credit facilities, net	102,200	(41,150)
Proceeds from exercise of stock options	375	4,331
Purchase of treasury stock	(98,011)	0
Payment of contingent liability	0	(4,756)
Excess tax benefit from equity compensation plans	1,015	4,653
Other	(409)	(1,173)
Net cash provided by (used in) financing activities	5,170	(38,095)
Increase (decrease) in cash and cash equivalents	(19,808)	15,222
Cash and cash equivalents, beginning of year	24,299	4,022
Cash and cash equivalents, end of period	4,491	19,244
Cash paid during the period:
Interest	9,190	8,957
Income taxes	$ 140	$ 565