Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held for which no such other than temporary impairment (OTTI) was previously recognized.

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Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings.

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Securities (Other-Than-Temporary Impairment) (Details)	3 Months Ended
Securities (Other-Than-Temporary Impairment) (Details)	Mar. 31, 2019 USD ($) security	Mar. 31, 2018 USD ($)	Dec. 31, 2018 security
Other Than Temporary Impairment Credit Losses Recognized in Earnings
Impairment loss, Available-for-sale debt securities \| $	$ 0	$ 0
Number of available-for-sale debt securities in an unrealized loss position	151		184
Investment securities available-for-sale
Other Than Temporary Impairment Credit Losses Recognized in Earnings
OTTI credit losses \| $	$ 0	$ 0
Foreign bonds
Other Than Temporary Impairment Credit Losses Recognized in Earnings
Number of available-for-sale debt securities in an unrealized loss position	16		16
U.S. government agency and U.S. government sponsored enterprise mortgage-backed securities
Other Than Temporary Impairment Credit Losses Recognized in Earnings
Number of available-for-sale debt securities in an unrealized loss position	86		108
U.S. Treasury securities
Other Than Temporary Impairment Credit Losses Recognized in Earnings
Number of available-for-sale debt securities in an unrealized loss position	19		19