Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities
Net income	$ 97,330	$ 81,972	$ 71,993
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	13,359	11,592	9,746
Amortization	1,237	1,284	1,559
Share-based compensation	8,150	8,465	8,233
Excess tax benefits from share-based compensation	(4,611)	(4,487)	(3,118)
Provision for doubtful accounts receivable, net of write-offs	(930)	(422)	(1,202)
Provision for inventory obsolescence, net	(416)	447	(11)
Change in deferred income taxes	707	3,168	2,605
Loss on sale of property and equipment	97	44	263
Equity earnings in unconsolidated investments	(182)	(316)	(209)
(Gains) losses on foreign currency transactions	220	(111)	592
Goodwill impairment	0	6,946	1,550
Other	108	138	195
Changes in operating assets and liabilities, net of effects of acquisitions:
Receivables	(10,085)	(3,396)	(5,887)
Product inventories	(27,291)	(9,232)	(35,339)
Prepaid expenses and other assets	504	(1,159)	(2,951)
Accounts payable	14,007	20,253	6,402
Accrued expenses and other current liabilities	12,884	3,892	20,682
Net cash provided by operating activities	105,088	119,078	75,103
Investing activities
Acquisition of businesses, net of cash acquired	(1,244)	(4,699)	(5,934)
Purchases of property and equipment, net of sale proceeds	(18,742)	(16,271)	(19,454)
Other investments, net	125	(238)	(190)
Net cash used in investing activities	(19,861)	(21,208)	(25,578)
Financing activities
Proceeds from revolving line of credit	678,936	607,923	749,349
Payments on revolving line of credit	(715,400)	(524,341)	(700,749)
Proceeds from asset-backed financing	70,000	0	0
Payments on asset-backed financing	(18,000)	0	0
Payments on long-term debt and other long-term liabilities	(10)	(100,022)	(149)
Payments of deferred acquisition consideration	0	0	(500)
Payments of deferred financing costs	(1,044)	0	(1,674)
Excess tax benefits from share-based compensation	4,611	4,487	3,118
Proceeds from stock issued under share-based compensation plans	21,409	20,205	13,085
Payments of cash dividends	(33,808)	(29,135)	(26,470)
Purchases of treasury stock	(96,179)	(81,761)	(76,564)
Net cash used in financing activities	(89,485)	(102,644)	(40,554)
Effect of exchange rate changes on cash and cash equivalents	(199)	(250)	(1,205)
Change in cash and cash equivalents	(4,457)	(5,024)	7,766
Cash and cash equivalents at beginning of year	12,463	17,487	9,721
Cash and cash equivalents at end of year	$ 8,006	$ 12,463	$ 17,487