Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 217,611	$ 243,796
Receivables, net of allowance for credit loss of $35,103 and $38,113	2,874,463	2,449,577
Contract assets, net of allowance for credit loss	240,488	197,176
Prepaid expenses and other	77,547	51,152
Total current assets	3,410,109	2,941,701
Property and equipment, net of accumulated depreciation and amortization	174,119	178,949
Goodwill	1,483,560	1,487,187
Other intangible assets, net of accumulated amortization	105,969	113,910
Right-of-use lease assets	313,463	319,785
Deferred tax assets	24,572	18,640
Other assets	84,831	84,086
Total assets	5,596,623	5,144,258
Current liabilities:
Accounts payable	1,399,464	1,195,099
Outstanding checks	76,241	88,265
Accrued expenses:
Compensation	110,003	138,460
Transportation expense	177,618	153,574
Income taxes	71,056	43,700
Other accrued liabilities	150,337	154,460
Current lease liabilities	66,188	66,174
Current portion of debt	250,000	0
Total current liabilities	2,300,907	1,839,732
Long-term debt	1,093,517	1,093,301
Noncurrent lease liabilities	262,559	268,572
Noncurrent income taxes payable	24,682	26,015
Deferred tax liabilities	32,236	22,182
Other long-term liabilities	14,535	14,523
Total liabilities	3,728,436	3,264,325
Stockholders’ investment:
Preferred stock, $0.10 par value, 20,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.10 par value, 480,000 shares authorized; 179,206 and 179,232 shares issued, 133,243 and 134,298 outstanding	13,324	13,430
Additional paid-in capital	568,209	566,022
Retained earnings	4,476,532	4,372,833
Accumulated other comprehensive loss	(53,284)	(45,998)
Treasury stock at cost (45,963 and 44,934 shares)	(3,136,594)	(3,026,354)
Total stockholders’ investment	1,868,187	1,879,933
Total liabilities and stockholders’ investment	$ 5,596,623	$ 5,144,258