Schedule II - Valuation and Qualifying Accounts Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts Receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 1,719	$ 1,126	$ 565
Provision for doubtful accounts	442	976	1,143
Write-off of accounts receivable against allowance	(1,004)	(725)	(586)
Other	0	342	4
Ending balance	1,157	1,719	1,126
Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	0	(6,626)	(10,431)
Decrease (increase)	0	6,626	3,805
Ending balance	$ 0	$ 0	$ (6,626)