Consolidated Statement Of Cash Flows $ in Thousands	12 Months Ended
	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jan. 31, 2015 USD ($)
Cash flows from operating activities:
Cash received from customers	$ 29,427,357	$ 28,119,687	$ 29,380,493
Cash paid to vendors and employees	(28,664,222)	(27,819,886)	(29,174,581)
Interest paid, net	(22,020)	(20,264)	(24,546)
Income taxes paid	(84,272)	(85,645)	(58,275)
Net cash provided by operating activities	656,843	193,892	123,091
Cash flows from investing activities:
Acquisition of businesses, net of cash acquired	(2,916)	(27,848)	0
Expenditures for property and equipment	(24,971)	(20,917)	(18,639)
Proceeds from sale of fixed assets	0	0	7,121
Software and software development costs	(14,364)	(13,055)	(9,536)
Proceeds from sale of subsidiaries	0	20,020	0
Net cash used in investing activities	(42,251)	(41,800)	(21,054)
Cash flows from financing activities:
Payments for employee withholdings on equity awards	(4,479)	(4,662)	(2,961)
Proceeds from the reissuance of treasury stock	733	561	1,456
Cash paid for debt issuance costs	21,581	0	0
Cash paid for purchase of treasury stock	0	(147,003)	(52,997)
Proceeds from issuance of Senior Notes	998,405	0	0
Acquisition earn-out payments	0	(2,736)	(5,060)
Net borrowings on revolving credit loans	3,417	5,912	7,269
Principal payments on long-term debt	0	(319)	(546)
Net cash provided by (used in) financing activities	976,495	(148,247)	(52,839)
Effect of exchange rate changes on cash and cash equivalents	3,335	(15,671)	(72,057)
Net increase (decrease) in cash and cash equivalents	1,594,422	(11,826)	(22,859)
Cash and cash equivalents at beginning of year	531,169	542,995	570,101
Less: Cash balance of businesses held for sale at end of year	0	0	4,247
Cash and cash equivalents at end of year	2,125,591	531,169	542,995
Reconciliation of net income to net cash provided by operating activities:
Net income	195,095	265,736	175,172
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on disposal of subsidiaries	0	699	1,330
Depreciation and amortization	54,437	57,253	68,746
Provision for losses on accounts receivable	5,026	6,061	10,415
Stock-based compensation expense	13,947	14,890	13,668
Accretion of debt discount and debt issuance costs on Senior Notes	835	839	839
Deferred income taxes	(11,002)	2,387	(335)
Gain on sale of fixed assets	0	0	(2,350)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(91,961)	(297,637)	22,166
Inventories	(20,838)	(219,482)	245,474
Prepaid expenses and other assets	66,027	(44,384)	31,254
Accounts payable	459,146	426,412	(469,757)
Accrued expenses and other liabilities	(13,869)	(18,882)	26,469
Total adjustments	461,748	(71,844)	(52,081)
Net cash provided by operating activities	$ 656,843	$ 193,892	$ 123,091