Acquisitions (Details 2) (Total Logistic Control [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2010
Total Logistic Control [Member]
Assets:
Current Assets	$ 24,249
Current Assets Purchase Accounting Adjustments	339
Current Assets Final Allocation	24,588
Operating property and equipment	75,471
Operating property and equipment Purchase Accounting Adjustments	(2,336)
Operating property and equipment Final Allocation	73,135
Goodwill	138,321
Goodwill Purchase Accounting Adjustments	(6,410)
Goodwill Final Allocation	131,911
Customer relationships and other intangibles	35,380
Customer relationships and other intangibles Purchase Accounting Adjustments	(400)
Customer relationships and other intangibles Final Allocation	34,980
Other assets	632
Other assets Purchase Accounting Adjustments	184
Other assets Final Allocation	816
Assets	274,053
Assets Purchase Accounting Adjustments	(8,623)
Assets Final Allocation	265,430
Liabilities:
Current liabilities	(26,575)
Current liabilities Purchase Accounting Adjustments	(300)
Current liabilities Final Allocation	(26,875)
Deferred income taxes	(38,883)
Deferred income taxes Purchase Accounting Adjustments	7,451
Deferred income taxes Final Allocation	(31,432)
Liabilities	(65,458)
Liabilities Purchase Accounting Adjustments	7,151
Liabilities Final Allocation	(58,307)
Net asset acquired	208,595
Net assets acquired Purchase Accounting Adjustments	1,472
Net assets acquired Final Allocation	$ 207,123