Consolidated Statement Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015
Cash flows from operating activities:
Cash received from customers	$ 21,076,446	$ 20,055,571
Cash paid to vendors and employees	(20,776,017)	(19,748,997)
Interest paid, net	(18,982)	(17,759)
Income taxes paid	(69,960)	(62,741)
Net cash provided by operating activities	211,487	226,074
Cash flows from investing activities:
Expenditures for property and equipment	(18,785)	(13,943)
Software and software development costs	(12,118)	(9,234)
Acquisition of businesses, net of cash acquired	(2,685)	(27,848)
Proceeds from sale of subsidiaries	0	20,020
Net cash used in investing activities	(33,588)	(31,005)
Cash flows from financing activities:
Net (repayments) borrowings on revolving credit loans	(1,476)	5,170
Acquisition-related financing costs	(14,988)	0
Payments for employee tax withholdings on equity awards	(4,385)	(4,533)
Proceeds from the reissuance of treasury stock	492	376
Cash paid for purchase of treasury stock	0	(147,003)
Principal payments on long-term debt	0	(319)
Acquisition earn-out payment	0	(2,736)
Net cash used in financing activities	(20,357)	(149,045)
Effect of exchange rate changes on cash and cash equivalents	2,854	(3,059)
Net increase in cash and cash equivalents	160,396	42,965
Cash and cash equivalents at beginning of year	531,169	542,995
Cash and cash equivalents at end of period	691,565	585,960
Reconciliation of net income to net cash provided by operating activities:
Net income	116,273	169,589
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on disposal of subsidiaries	0	699
Depreciation and amortization	41,223	42,518
Provision for losses on accounts receivable	3,457	5,041
Stock-based compensation expense	(11,020)	(11,399)
Accretion of debt discount and debt issuance costs on Senior Notes	626	630
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	91,938	(158,020)
Inventories	(148,116)	(177,643)
Prepaid expenses and other assets	57,178	(22,405)
Accounts payable	109,404	397,721
Accrued expenses and other liabilities	(71,516)	(43,455)
Total adjustments	95,214	56,485
Net cash provided by operating activities	$ 211,487	$ 226,074