Summary of Significant Accounting Policies (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable
Balance, beginning of year	$ 3,147	$ 2,421	$ 1,837
Additions (reductions) to expense	(354)	1,039	844
Write-offs	(280)	(174)	(239)
Other	(154)	(139)	(21)
Balance, end of year	$ 2,359	$ 3,147	$ 2,421