Line of Credit, Number of Agreement

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

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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.

+ Details

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- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Fair value of asset after deduction of liability.

+ References

No definition available.

+ Details

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- Definition

The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 8B
-URI http://asc.fasb.org/extlink&oid=82897076&loc=SL6284393-111563

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Fair Value Measurement (Narrative) (Details)	3 Months Ended		6 Months Ended		12 Months Ended
Fair Value Measurement (Narrative) (Details)	Jun. 30, 2018 USD ($) Agreement	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Agreement	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Credit Derivatives [Line Items]
Transfer of equity securities from Level 2 to Level 1	$ 0	$ 35,400,000	$ 0	$ 35,400,000
Net impairment losses recognized in earnings	404,000	$ 0	404,000	$ 171,000
Fair value of funded deferred compensation assets	$ 22,300,000		$ 22,300,000		$ 20,200,000
Number of line of credit agreement \| Agreement	2		2
Corporate debt, limited observable inputs \| NRSRO \| NRSRO, Rating BBB
Credit Derivatives [Line Items]
Credit rating			76.00%
Corporate debt, limited observable inputs \| NRSRO \| NRSRO, Rating BBBplus
Credit Derivatives [Line Items]
Credit rating					84.00%
Residential mortgage-backed and other asset-backed securities \| NRSRO \| NRSRO, Rating AAA
Credit Derivatives [Line Items]
Credit rating			70.00%		21.00%
Early Stage Business Development \| Investment in unconsolidated subsidiaries
Credit Derivatives [Line Items]
Net impairment losses recognized in earnings					$ 8,500,000
Fair Value, Measurements, Nonrecurring
Credit Derivatives [Line Items]
Fair value, net asset (liability)	$ 0		$ 0		$ 1,200,000