Other intangibles, net (Customer relationships and tradename and related accumulated amortization) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 400,000	$ 400,000
Accumulated amortization	(113,188)	(82,012)
Finite-lived intangible assets	286,812	317,988
Customer Relationships, Net [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	360,000	360,000
Accumulated amortization	(76,882)	(55,706)
Finite-lived intangible assets	283,118	304,294
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	40,000	40,000
Accumulated amortization	(36,306)	(26,306)
Finite-lived intangible assets	$ 3,694	$ 13,694

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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