Acquisitions - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	May. 19, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill Acquisition Related Escrow Funding	$ 78,694			$ 78,694	$ 0
Gain on derivative instruments	$ 85,187	$ 0	$ 0	85,187	0
Intangibles adjustment				182,993
Deferred tax liability adjustment				57,072
Other adjustments				258
Goodwill adjustment				126,179
Amortization expense adjustment				8,067
Transaction costs				26,617
Interest expense		33,003	$ 17,498	88,927	$ 52,396
Current portion of escrow		$ 76,263		76,263		$ 5,583
Wood Mackenzie
Business Acquisition [Line Items]
Percent of corporate wholly-owned subsidiaries	100.00%
Net cash purchase price	$ 2,889,629
Interest expense				$ 13,336