Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

No definition available.

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- 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.

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- Definition

Future minimum rental payments in aggregate as of the balance sheet date under operating leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84164653&loc=d3e41551-112718

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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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Basis of Presentation and Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect adjustment for adoption of new accounting standards				$ 0
Net unrealized loss on equity investments	$ 642	$ 0
Future minimum lease payments				3,600
Retained Earnings
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect adjustment for adoption of new accounting standards				$ 13,627
Retained Earnings \| Accounting Standards Update 2018-02
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect adjustment for adoption of new accounting standards			$ 3,100
Retained Earnings \| Accounting Standards Update 2016-01
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cumulative effect adjustment for adoption of new accounting standards			$ 16,800