Investments in Qualified Affordable Housing Projects (Details) - USD ($)	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Investment In Qualified Affordable Housing Projects.
Tax Credits and Benefits	$ 1,200,000	$ 771,000,000
Amortization		587,000,000,000
Share of book losses	1,000,000
Carrying value	38,700,000	26,200,000
Original Investment Value	49,700,000	49,700,000
Funding obligation	17,900,000	$ 9,400,000
Amount repaid	$ 0

Amount repaid of investment in qualified affordable housing projects.

No definition available.

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- Definition

Amount of obligation related to Affordable Housing Program (AHP) assessments required by the Federal Home Loan Bank Act of 1932.

+ References

No definition available.

+ Details

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- Definition

Amount of affordable housing tax credits and other tax benefits recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985

+ Details

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- Definition

Amount of investment in qualified affordable housing projects.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985

+ Details

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- Definition

Amount of amortization expense of investment in qualified affordable housing projects.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985

+ Details

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- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ 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 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Amount of investment income (loss) of qualified affordable housing project investments accounted for using the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64813897&loc=SL49122993-202985

+ Details

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- References

No definition available.

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