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
Valuation and qualifying accounts
Balance at Beginning of Year	$ 2,086	$ 1,743	$ 1,554
Additions	848	990	891
Deductions, Recoveries & Other	(15)	(647)	(702)
Balance at Ending of Year	2,919	2,086	1,743
Tax valuation allowance
Valuation and qualifying accounts
Balance at Beginning of Year	11,839	7,335	6,073
Additions	2,965	8,831	3,213
Deductions, Recoveries & Other	(183)	(4,327)	(1,951)
Balance at Ending of Year	$ 14,621	$ 11,839	$ 7,335