Acquisitions (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Jul. 02, 2015	Jun. 17, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 686,359			$ 599,863
IME [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents			$ 33,279
Payments to Acquire Businesses, Gross	$ 76,700
Goodwill			30,193
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	49,941
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 3,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets			17,082
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			35,130
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets			5,234
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			90,725
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable			(1,958)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other			(1,548)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Settlement Obligations and Customer Deposits			(27,700)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent			(9,142)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities			(859)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			(41,207)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net			79,711
XE [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		$ 1,872
Payments to Acquire Businesses, Gross	$ 79,900
Goodwill		103,887
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	642,912
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 40,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets		1,294
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		15,367
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		341
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		28,510
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable		(26)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other		(11,824)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities		(571)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		(12,421)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		119,976
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets Noncurrent		9,636
Software Development [Member] | XE [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		2,011
Customer-Related Intangible Assets [Member] | IME [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	8 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			33,940
Customer-Related Intangible Assets [Member] | XE [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	8 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		9,414
Trade Names [Member] | IME [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			650
Trade Names [Member] | XE [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	20 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		3,654
Noncompete Agreements [Member] | IME [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			$ 540
Noncompete Agreements [Member] | XE [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 288