Business Acquisition (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Goodwill, Purchase Accounting Adjustments	$ (800,000)
Goodwill, Acquired During Period	40,557,000
Goodwill	669,374,000	635,675,000
Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount	20,400,000
Business Acquisition Contributed Total Revenue	2,938,000
Total consideration of transaction, net of cash acquired	$ 73,467,000