Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 28, 2015	Dec. 27, 2014
Current Assets
Cash and cash equivalents	$ 114,887	$ 163,944
Short-term investments	37,174	37,007
Trade accounts receivable, less allowance of $4,248 and $4,338	447,696	492,642
Other receivables, including advances to independent contractors, less allowance of $4,235 and $4,189	29,437	15,132
Deferred income taxes and other current assets	11,475	23,603
Total current assets	640,669	732,328
Operating property, less accumulated depreciation and amortization of $165,007 and $160,681	197,085	202,203
Goodwill	31,134	31,134
Other assets	78,758	78,547
Total assets	947,646	1,044,212
Current Liabilities
Cash overdraft	28,410	34,629
Accounts payable	196,215	220,077
Current maturities of long-term debt	34,432	35,064
Insurance claims	24,791	24,233
Dividends payable		44,794
Other current liabilities	42,126	51,654
Total current liabilities	325,974	410,451
Long-term debt, excluding current maturities	67,671	76,257
Insurance claims	22,532	21,769
Deferred income taxes and other noncurrent liabilities	47,144	47,474
Shareholders' Equity
Common stock, $0.01 par value, authorized 160,000,000 shares, issued 67,349,642 and 67,268,817 shares	673	673
Additional paid-in capital	189,525	189,012
Retained earnings	1,282,277	1,255,374
Cost of 22,938,800 and 22,474,331 shares of common stock in treasury	(986,913)	(955,613)
Accumulated other comprehensive loss	(1,237)	(1,185)
Total shareholders' equity	484,325	488,261
Total liabilities and shareholders' equity	$ 947,646	$ 1,044,212