Acquisitions and Divestitures (Narrative) (Details) - USD ($)						3 Months Ended		9 Months Ended
	Sep. 07, 2016	Feb. 29, 2016	Jan. 08, 2016	May 18, 2015	Jan. 08, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Revenue period for earnout provision		5 years
Earnout income recognized								$ 0
Goodwill						$ 1,965,024,000		1,965,024,000		$ 1,962,722,000
Norskale [Member]
Finite-Lived Intangible Assets [Line Items]
Preliminary consideration	$ 11,500,000
Cash acquired in business combination	800,000
Transaction costs	400,000
Goodwill	2,900,000
2016 Asset Acquisition [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired			$ 23,600,000
Sanbolic, Inc. [Member]
Finite-Lived Intangible Assets [Line Items]
Preliminary consideration					$ 89,400,000
Cash acquired in business combination					200,000
Transaction costs					$ 500,000
Conversion of assumed non-vested stock units to shares of Company stock (shares)					37,057
Grasshopper Group, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Preliminary consideration				$ 161,500,000
Cash acquired in business combination				$ 3,600,000
Conversion of assumed non-vested stock units to shares of Company stock (shares)				105,765
General and Administrative Expense [Member] | Norskale [Member]
Finite-Lived Intangible Assets [Line Items]
Acquisition related costs						$ 300,000		$ 400,000
General and Administrative Expense [Member] | Sanbolic, Inc. [Member]
Finite-Lived Intangible Assets [Line Items]
Acquisition related costs							$ 0		$ 200,000
General and Administrative Expense [Member] | Grasshopper Group, LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Acquisition related costs							$ 0		$ 300,000
Core and Product Technologies [Member] | Norskale [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 8,200,000
Weighted average useful life	4 years