Segment Information - Segment Description (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 330,007	$ 371,080	$ 973,344	$ 1,112,608
Diversified Industrial net sales
Segment Reporting Information [Line Items]
Operating Expenses		2,692		8,076
Energy net revenue
Segment Reporting Information [Line Items]
Operating Expenses		424		1,272
Financial Services revenue
Segment Reporting Information [Line Items]
Operating Expenses		(206)		618
Corporate and Other
Segment Reporting Information [Line Items]
Operating Expenses		(206)		618
Management Fee | Diversified Industrial net sales
Segment Reporting Information [Line Items]
Total revenue	7,071	8,988	21,214	26,963
Management Fee | Energy net revenue
Segment Reporting Information [Line Items]
Total revenue	1,316	2,164	3,947	6,493
Management Fee | Financial Services revenue
Segment Reporting Information [Line Items]
Total revenue	$ 408	$ 741	$ 1,270	$ 2,224