Consolidated Statements of Operations (Parenthetical) - USD ($)	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Parent Company [Member]
Trading Securities, Change in Unrealized Holding Gain (Loss)	$ (2,200,000)	$ 384,000

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