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Accounting Pronouncements Accounting Pronouncements (Details) - USD ($) $ in Thousands | 3 Months Ended
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Mar. 31, 2018 | Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Undistributed gains of equity method investments | $ (881) | $ (685)
Distributions in excess of current year income of equity method investments | 1,346 | 465
Decrease (increase) in other assets | (9,672) | (6,511)
Net cash provided by operating activities | (7,705) | 24,531
Distributions from other investments | 6,221 | 5,983
Net cash used in investing activities | (59,455) | (32,904)
Scenario, Previously Reported [Member] |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Undistributed gains of equity method investments |  | (665)
Distributions in excess of current year income of equity method investments |  | 0
Decrease (increase) in other assets |  | 15,998
Net cash provided by operating activities |  | 46,595
Distributions from other investments |  | 6,428
Net cash used in investing activities |  | (32,459)
AOCI Attributable to Parent [Member] |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Cumulative effect of new accounting principle in period of adoption | (25,019) |
AOCI Attributable to Parent [Member] | Accounting Standards Update 2016-01 [Member] |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Cumulative effect of new accounting principle in period of adoption | (30,700) | 0
AOCI Attributable to Parent [Member] | Accounting Standards Update 2018-02 [Member] |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Cumulative effect of new accounting principle in period of adoption | $ 5,700 | $ 0

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