Goodwill and Other Intangible Assets - Analysis of Goodwill and intangible assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, beginning of year	$ 415,936	$ 396,245	$ 392,882
Goodwill, acquired during period	807,381	25,159
Foreign currency translation, goodwill	(9,687)	(5,468)	3,363
Goodwill, end of year	1,213,630	415,936	396,245
Intangible assets with an indefinite life, beginning of year	15,366	15,366	15,366
Indefinite-lived Intangible Assets Acquired	673,000
Foreign currency translation, indefinite-lived intangible assets	(5,507)
Intangible assets with an indefinite life, end of year	682,859	15,366	15,366
Intangible assets with a definite life, beginning of year	16,650	0	279
Finite-lived Intangible Assets Acquired	315,000	18,500
Amortization	(15,517)	(1,850)	(279)
Foreign currency translation, intangible assets with an definite life	(2,356)
Intangible assets with a definite life, end of year	313,777	16,650	0
Goodwill and other intangible assets, beginning of year	447,952	411,611	408,527
Additions	1,795,381	43,659
Foreign currency translation, intangible assets including goodwill	(17,550)
Goodwill and other intangible assets, end of year	$ 2,210,266	$ 447,952	$ 411,611