Changes in Accumulated Other Comprehensive Income / (Loss) by Component (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in Accumulated Other Comprehensive Loss [Roll Forward]
Balance, Beginning of Period	$ 3,899,899	$ 3,940,888	$ 4,855,776
Other Comprehensive Income (Loss)	1,672	12,228	(76,696)
ASU 2018-02 Reclassification	0
Ending Balance – Accumulated OCI	(7,904)	(8,476)
Accumulated Other Comprehensive Income (Loss)
Changes in Accumulated Other Comprehensive Loss [Roll Forward]
Balance, Beginning of Period	(8,476)	$ (392,556)	$ (315,598)
Other Comprehensive Income before Reclassifications	1,736
Amounts Reclassified from Accumulated Other Comprehensive Loss, net of tax	(64)
Other Comprehensive Income (Loss)	1,672
ASU 2018-02 Reclassification	$ 1,100

Tax Cuts And Jobs Act Of 2017 Reclassification From AOCI To Retained Earnings Tax Effect

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Amount before tax and reclassification adjustments of other comprehensive income (loss).

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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