BUSINESS SEGMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment reporting information
Revenue, net	$ 301,426	$ 255,352	$ 906,624	$ 757,255
Cost of goods sold	242,276	208,810	730,699	620,036
Gross profit	59,150	46,542	175,925	137,219
Operating expenses	(55,692)	(44,767)	(160,887)	(132,950)
Other income (expense), net	166	1,049	339	1,795
Provision for income taxes	91	131	449	182
Net income	3,533	2,693	14,928	5,882	23,715	2,473
Direct
Segment reporting information
Revenue, net	35,681	34,215	113,873	109,048
Cost of goods sold	30,777	30,684	99,768	99,422
Gross profit	4,904	3,531	14,105	9,626
Fulfillment partner
Segment reporting information
Revenue, net	265,745	221,137	792,751	648,207
Cost of goods sold	211,499	178,126	630,931	520,614
Gross profit	54,246	43,011	161,820	127,593
Inter-segment
Segment reporting information
Revenue, net	$ 0	$ 0	$ 0	$ 0