CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Apr. 01, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 568,632	$ 438,319
Short-term investments	1,597,903	1,591,740
Trade receivables	665,464	715,292
Merchandise inventories	1,735,861	1,722,392
Prepaid expenses	45,535	50,434
Total current assets	4,613,395	4,518,177
Long-term investments	5,461,917	5,146,878
Other noncurrent assets	541,957	434,280
Property, plant and equipment	12,187,185	11,981,632
Accumulated depreciation	(4,778,233)	(4,694,509)
Net property, plant and equipment	7,408,952	7,287,123
Total assets	18,026,221	17,386,458
Current liabilities:
Accounts payable	1,730,028	1,609,652
Accrued expenses:
Contributions to retirement plans	266,577	525,668
Self-insurance reserves	140,539	139,554
Salaries and wages	165,404	127,856
Other	329,056	414,197
Current portion of long-term debt	127,070	113,999
Federal and state income taxes	232,821	12,787
Total current liabilities	2,991,495	2,943,713
Deferred tax liabilities	417,286	396,484
Self-insurance reserves	217,408	216,125
Accrued postretirement benefit cost	102,779	102,540
Long-term debt	115,928	136,585
Other noncurrent liabilities	94,276	93,574
Total liabilities	3,939,172	3,889,021
Common stock related to Employee Stock Ownership Plan (ESOP)	3,484,220	3,068,097
Stockholders’ equity:
Common stock of $1 par value. Authorized 1,000,000 shares; issued 770,415 shares in 2017 and 763,198 shares in 2016	770,415	763,198
Additional paid-in capital	3,139,647	2,849,947
Retained earnings	10,222,245	9,836,696
Treasury stock at cost, 2,820 shares in 2017	(115,343)	0
Accumulated other comprehensive earnings	43,158	23,427
Common stock related to ESOP	(3,484,220)	(3,068,097)
Total stockholders’ equity	10,575,902	10,405,171
Noncontrolling interests	26,927	24,169
Total equity	14,087,049	13,497,437
Total liabilities and stockholders' equity	$ 18,026,221	$ 17,386,458