Segment Information - Segment Description (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 295,437	$ 385,715	$ 643,337	$ 741,528
Diversified industrial net sales
Segment Reporting Information [Line Items]
Operating Expenses		2,692		5,384
Energy net revenue
Segment Reporting Information [Line Items]
Operating Expenses		424		848
Financial services revenue
Segment Reporting Information [Line Items]
Operating Expenses		(206)		412
Corporate and Other
Segment Reporting Information [Line Items]
Operating Expenses		(206)		412
Management Fee | Diversified industrial net sales
Segment Reporting Information [Line Items]
Total revenue	5,430	11,873	14,142	17,975
Management Fee | Energy net revenue
Segment Reporting Information [Line Items]
Total revenue	1,058	1,867	2,632	4,329
Management Fee | Financial services revenue
Segment Reporting Information [Line Items]
Total revenue	$ 12	$ 514	$ 862	$ 1,482