Securities - Trading Securities (Details) - USD ($)	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Trading Securities
Unrealized gains included in trading securities	$ 1,700,000	$ 661,000

Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

No definition available.

Name:	us-gaap_TradingSecuritiesUnrealizedHoldingGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration