Geographic Data (Net Sales By Major Product Category) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Dec. 31, 2010	Oct. 02, 2010	Jul. 03, 2010	Apr. 03, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenue from External Customer [Line Items]
Net sales	$ 247,308	$ 253,338	$ 245,541	$ 237,301	$ 234,019	$ 229,807	$ 218,558	$ 211,975	$ 983,488	$ 894,359	$ 738,482
Hardware [Member]
Revenue from External Customer [Line Items]
Net sales									743,308	676,738	534,993
Supplies [Member]
Revenue from External Customer [Line Items]
Net sales									187,457	167,633	155,847
Service And Software [Member]
Revenue from External Customer [Line Items]
Net sales									47,206	44,829	42,379
Shipping And Handling [Member]
Revenue from External Customer [Line Items]
Net sales									$ 5,517	$ 5,159	$ 5,263