Goodwill and Other Intangible Assets (Schedule of Intangible Assets and Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other intangible assets
Gross amount	$ 148,395	$ 148,395
Accumulated impairment losses and amortization	(82,937)	(65,495)
Intangible Assets, Net, Excluding Goodwill [Roll Forward]
Other intangible assets, Net, Beginning of Period	82,900
Other intangible assets, Net, End of Period	65,458	82,900
Intangible Assets, Net, Including Goodwill [Roll Forward]
Goodwill and Other intangible assets, Net, Beginning of Period	265,154
Goodwill and Other intangible assets, Net, End of Period	251,186	265,154
Excluding Equity Method Investments
Goodwill
Goodwill, Gross amount	199,889	199,889	$ 8,160
Accumulated impairment losses and amortization	(2,299)	(2,299)	(2,299)
Goodwill [Roll Forward]
Goodwill, Net, Beginning of Period	197,590	5,861
Acquired during the year		191,729
Goodwill, Net, End of Period	197,590	197,590
Other intangible assets
Gross amount	96,599	96,599	12,999
Accumulated impairment losses and amortization	(43,003)	(29,035)	(10,958)
Intangible Assets, Net, Excluding Goodwill [Roll Forward]
Other intangible assets, Net, Beginning of Period	67,564	2,041
Acquired during the year		83,600
Amortization	(13,968)	(18,077)
Other intangible assets, Net, End of Period	53,596	67,564
Goodwill and Other intangible assets, Total
Gross amount, Beginning of Period	296,488	296,488	21,159
Accumulated impairment losses and amortization, Beginning of Period	(45,302)	(31,334)	$ (13,257)
Intangible Assets, Net, Including Goodwill [Roll Forward]
Goodwill and Other intangible assets, Net, Beginning of Period	265,154	7,902
Acquired during the year		275,329
Amortization	(13,968)	(18,077)
Goodwill and Other intangible assets, Net, End of Period	$ 251,186	$ 265,154