Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash	$ 9,006	$ 16,030
Accounts receivable, net	146,134	120,001
Operating supplies	7,277	7,171
Prepaid expenses	14,493	13,862
Other current assets	1,863	3,870
Total current assets	178,773	160,934
Property and equipment:
Land and land improvements	16,263	16,135
Buildings and leasehold improvements	37,676	36,532
Equipment	534,711	504,527
Property and equipment	588,650	557,194
Less accumulated depreciation	409,214	390,772
Property and equipment, net	179,436	166,422
Other assets	31,354	31,949
Identified intangible assets and goodwill, net	34,376	34,281
Total assets	423,939	393,586
Current liabilities:
Short-term debt	16,701	15,501
Current portion of capital leases	170	0
Accounts payable	41,283	37,750
Accrued expenses	37,659	36,146
Self-insurance accruals	23,092	22,553
Total current liabilities	118,905	111,950
Long-term debt	72,194	60,801
Senior unsecured notes	17,923	23,832
Capital leases	2,173	0
Self-insurance accruals	39,746	37,786
Other liabilities	20,819	17,678
Total liabilities	271,760	252,047
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, 2016 and 2015	21,457	21,457
Additional paid-in capital	23,886	17,815
Common shares subscribed	8,209	8,591
Retained earnings	290,292	270,605
Accumulated other comprehensive loss	(12,162)	(13,394)
Stockholders' equity before treasury stock	331,682	305,074
Less: Cost of Common shares held in treasury; 8,995 shares in 2016 and 8,714 in 2015	176,530	159,429
Common shares subscription receivable	2,973	4,106
Common shareholders' equity	152,179	141,539
Total liabilities and shareholders' equity	$ 423,939	$ 393,586