Summary of Significant Accounting Policies Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Outgoing freight expenses	$ 48,497	$ 44,672	$ 40,896
Goodwill	$ 6,680	$ 6,680