Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 37,229	$ 37,392
Marketable securities	91,369	89,348
Accounts receivable, net	52,338	52,410
Inventories	240,193	226,191
Prepaid expenses	7,970	8,995
Income taxes recoverable	39	1,226
Deferred income taxes	885	0
Total current assets	430,023	415,562
Property and equipment, net	575,702	575,003
Goodwill	35,162	35,162
Intangible and other assets, net	3,280	3,277
Deferred income taxes	308	0
Total assets	1,044,475	1,029,004
Liabilities
Accounts payable	127,114	132,092
Accrued expenses	33,157	35,081
Accrued self-insurance	18,456	18,103
Deferred revenue, net	4,515	6,197
Income taxes payable	12,200	0
Deferred income taxes	4,034	4,130
Total current liabilities	199,476	195,603
Postretirement benefit obligations	15,185	14,434
Deferred income taxes	72,098	73,081
Total liabilities	286,759	283,118
Shareholders' Equity
Common stock, no par value, 100,800,000 shares authorized, 33,047,807 shares issued	9,949	9,949
Retained earnings	893,302	881,346
Accumulated other comprehensive income (Net of deferred taxes of $3,712 in 2012 and $3,800 in 2011)	5,322	5,448
Shareholders' equity before treasury stock	908,573	896,743
Treasury stock at cost, 6,149,364 shares	(150,857)	(150,857)
Total shareholders' equity	757,716	745,886
Total liabilities and shareholders' equity	$ 1,044,475	$ 1,029,004