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
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of the year	$ 2,408	$ 4,098	$ 1,024
Acquired Balances	0	0	1,221
Charged to Expenses	1,937	1,386	3,266
Deductions	(2,460)	(3,076)	(1,413)
Balance at end of the year	1,885	2,408	4,098
Deferred Income Tax Asset Valuation Allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of the year	1,487	1,381	0
Additions	33	106	1,381
Charged to Expenses	0	106
Deductions	(186)	0	0
Balance at end of the year	$ 1,334	$ 1,487	$ 1,381