Acquisitions - Cayan - Consideration and Recognized Assets and Liabilities (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 11, 2018	Sep. 30, 2018	Dec. 31, 2017
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 4,113,669	$ 3,264,071
Cayan
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash paid	$ 1,054,931
Fair value of total consideration transferred	1,054,931
Cash	16,856
Accounts receivable	16,846
Property, plant and equipment	20,321
Total acquired identifiable intangible assets	324,900
Other assets	3,822
Identifiable intangible assets	324,885
Total identifiable net assets	210,227
Deferred tax asset	4,187
Deferred tax liability	(141,291)
Other liabilities	(35,399)
Goodwill	844,704
Total identifiable assets acquired and liabilities assumed	$ 1,054,931
Adjustments to purchase price and recognized assets and liabilities
Increase in liabilities		1,700
Adjustment related to deferred tax assets		4,200
Adjustment related to deferred tax liabilities		27,500
Goodwill adjustment		$ 25,000