CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
CURRENT ASSETS:
Cash, cash equivalents and restricted cash		$ 89,602	$ 27,134
Accounts receivable, net of allowance of $1,053 in 2023 and $939 in 2022		227,122	301,622
Inventory		57,727	57,764
Prepaid supplies and other		33,555	31,956
TOTAL CURRENT ASSETS		408,006	418,476
Property and equipment, net		2,553,674	2,402,408
Customer incentive		73,828	79,650
Goodwill and acquired intangibles		490,088	492,642
Operating lease assets		66,329	74,070
Other assets		110,354	122,647
TOTAL ASSETS		3,702,279	3,589,893
CURRENT LIABILITIES:
Accounts payable		218,218	192,992
Accrued salaries, wages and benefits		60,272	56,498
Accrued expenses		11,371	12,466
Current portion of debt obligations		642	639
Current portion of lease obligations		22,524	23,316
Unearned revenue and grants		33,784	21,546
TOTAL CURRENT LIABILITIES		346,811	307,457
Long term debt		1,544,454	1,464,285
Stock obligations		1,509	695
Post-retirement obligations		33,702	35,334
Long term lease obligations		44,727	51,575
Other liabilities		56,020	62,861
Deferred income taxes		260,989	255,180
TOTAL LIABILITIES		2,288,212	2,177,387
Commitments and contingencies (Note H)
STOCKHOLDERS’ EQUITY:
Preferred stock, 20,000,000 shares authorized, including 75,000 Series A Junior Participating Preferred Stock		$ 0	$ 0
Common stock, shares outstanding (in shares)		71,451,610	72,327,758
Common stock, par value $0.01 per share; 150,000,000 shares authorized; 71,451,610 and 72,327,758 shares issued and outstanding in 2023 and 2022, respectively		$ 715	$ 723
Additional paid-in capital		964,026	986,303
Retained earnings		549,023	528,882
Accumulated other comprehensive loss		(99,697)	(103,402)
TOTAL STOCKHOLDERS’ EQUITY		1,414,067	1,412,506
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY		$ 3,702,279	$ 3,589,893