Condensed Consolidated Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net sales	$ 2,314.9	$ 2,225.1	$ 6,702.9	$ 5,987.4
Cost of goods sold	2,192.7	2,102.9	6,348.0	5,663.1
Gross profit	122.2	122.2	354.9	324.3
Warehousing and distribution expenses	68.4	61.7	198.0	173.4
Selling, general and administrative expenses	35.9	38.6	113.4	111.8
Amortization of intangible assets	0.7	0.8	2.4	2.1
Total operating expenses	105.0	101.1	313.8	287.3
Income from operations	17.2	21.1	41.1	37.0
Interest expense	(0.4)	(0.6)	(1.6)	(1.8)
Interest income	0.1	0.2	0.3	0.4
Foreign currency transaction losses, net	0	(1.4)	(0.1)	(0.6)
Income before income taxes	16.9	19.3	39.7	35.0
Provision for income taxes	(6.4)	(7.3)	(15.5)	(14.0)
Net income	$ 10.5	$ 12.0	$ 24.2	$ 21.0
Basic net income per common share (in dollars per share)	$ 0.92	$ 1.05	$ 2.12	$ 1.84
Diluted net income per common share (in dollars per share)	$ 0.90	$ 1.03	$ 2.08	$ 1.78
Basic weighted-average shares	11.5	11.4	11.4	11.4
Diluted weighted-average shares	11.7	11.7	11.6	11.8
Dividends declared and paid per common share	$ 0.17	$ 0.00	$ 0.51	$ 0.00