Investment Securities Summary of Gains and Losses from Equity and Debt Securities, and Losses from Other-than-Temporary Impairment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Gain (Loss) on Investments [Line Items]
Gross Realized Gains	$ 4,829	$ 2	$ 7,385	$ 1,061
Gross Realized Losses	(232)	0	(246)	(36)
Net Gains (Losses)	4,597	2	7,139	1,025
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Gross Realized Gains	4,817	2	7,167	739
Gross Realized Losses	0	0	0	(10)
Net Gains (Losses)	4,817	2	7,167	729
Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Gross Realized Gains	12	0	218	322
Gross Realized Losses	(232)	0	(246)	(26)
Net Gains (Losses)	$ (220)	$ 0	$ (28)	$ 296

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

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