| **Intangible Assets and Goodwill (Intangibles Subject to Amortization) (Details) - USD ($) $ in Thousands** | Mar. 31, 2018 | Dec. 31, 2017 |
|-------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Finite-Lived Intangible Assets [Line Items]**                                                             |          |          |
| Gross carrying amount                                                                                       | $ 591,587     |          |
| Accumulated amortization                                                                                    | (47,172)      |          |
| Net carrying amount                                                                                         | 544,415       | $ 4,237       |
| Customer relationships                                                                                      |          |          |
| **Finite-Lived Intangible Assets [Line Items]**                                                             |          |          |
| Gross carrying amount                                                                                       | 483,267       |          |
| Accumulated amortization                                                                                    | (26,462)      |          |
| Net carrying amount                                                                                         | 456,805       |          |
| Other amortizable intangibles                                                                               |          |          |
| **Finite-Lived Intangible Assets [Line Items]**                                                             |          |          |
| Gross carrying amount                                                                                       | 108,320       |          |
| Accumulated amortization                                                                                    | (20,710)      |          |
| Net carrying amount                                                                                         | $ 87,610      |          |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.
+ References
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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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.
+ References
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
+ Details**Name:**us-gaap_FiniteLivedIntangibleAssetsGross**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_FiniteLivedIntangibleAssetsLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.
+ References
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
+ Details**Name:**us-gaap_FiniteLivedIntangibleAssetsNet**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_OtherIntangibleAssetsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |