Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash	$ 16,030	$ 18,415
Accounts receivable, net	120,001	111,598
Operating supplies	7,171	6,968
Prepaid expenses	13,862	14,088
Other current assets	3,870	7,200
Total current assets	160,934	158,269
Property and equipment:
Land and land improvements	16,135	16,553
Buildings and leasehold improvements	36,532	33,644
Equipment	504,527	482,752
Property and equipment	557,194	532,949
Less accumulated depreciation	390,772	372,066
Property and equipment, net	166,422	160,883
Other assets	32,420	27,789
Identified intangible assets and goodwill, net	34,281	34,063
Total assets	394,057	381,004
Current liabilities:
Short-term debt	15,501	8,281
Accounts payable	37,750	42,140
Accrued expenses	36,146	34,925
Self-insurance accruals	22,553	23,007
Total current liabilities	111,950	108,353
Long-term debt	61,104	51,306
Senior unsecured notes	24,000
Senior unsecured notes	30,000	30,000
Self-insurance accruals	37,786	35,886
Other liabilities	17,678	18,968
Total liabilities	252,518	244,513
Common shareholders' equity:
Common shares, $1.00 par value, per share; 48,000 shares authorized; 21,457 shares issued and outstanding before treasury shares as of December 31, 2015 and 2014	21,457	21,457
Additional paid-in capital	17,815	9,461
Common shares subscribed	8,591	9,381
Retained earnings	270,605	251,470
Accumulated other comprehensive loss	(13,394)	(11,523)
Stockholders' equity before treasury stock	305,074	280,246
Less: Cost of Common shares held in treasury; 8,714 shares in 2015 and 8,292 in 2014	159,429	138,155
Common shares subscription receivable	4,106	5,600
Common shareholders' equity	141,539	136,491
Total liabilities and shareholders' equity	$ 394,057	$ 381,004