Securities - Realized Gains (Losses) for Securities (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Marketable Securities [Abstract]
Net gains (losses) recognized during the period on equity securities	$ 100	$ (15)
Less: Net gains (losses) recognized during the period on equity securities sold during the period	0	0
Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting date	$ 100	$ (15)

Amount of unrealized holding loss before gain recognized in the income statement for investments in trading securities.

No definition available.

Name:	us-gaap_TradingSecuritiesUnrealizedHoldingLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration