Acquisitions (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of allocated purchase price paid to fair value of acquired net assets for acquisitions
Goodwill	$ 686,987	$ 669,652
2014 [Member]
Schedule of allocated purchase price paid to fair value of acquired net assets for acquisitions
Accounts receivable	68,128
Other current assets	7,660
Property and equipment	29,892
Goodwill	153,522
Customer relationship intangible assets	54,347
Accounts payable and other liabilities	82,644
Total	$ 230,905