Significant Accounting Policies (Details Textual) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Consolidated Accounts Receivable Percentage			10.00%		10.00%
Consolidated Largest Client Revenue	10.00%	10.00%	10.00%	10.00%
Restricted Cash and Cash Equivalents, Noncurrent	$ 46		$ 46		$ 47
Business Acquisition, Increase (Decrease) in Contingent Purchase Price Obligation	718	13,631	5,400	20,126
Business Combination, Acquisition Related Costs	427	811	1,438	2,481
Assets	1,365,687	1,351,741	1,365,687	1,351,741	1,344,945
Liabilities	1,405,784		1,405,784		1,311,802
Stock Issued During Period, Shares, Restricted Stock Award, Gross			469,224
Aggregate Grant Date Fair Value			7,868
Employee Stock Option [Member]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			852,000
Common Class A [Member]
Stock Issued During Period, Shares, Restricted Stock Award, Gross			801,519
Doner [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage			30.00%
Ownership Interest Percentage Increase On Exercise Of Option			70.00%
Assets	232,341		232,341
Liabilities	185,322		185,322
Stock Appreciation Rights [Member]
Potential Cash Settlement	$ 22,180		$ 22,180