Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2017

Financial Instruments, Owned, at Fair Value [Abstract]

Estimated Fair Values of Financial Instruments

The following table presents the fair values of financial instruments:

	December 31,
	2017		2016
	(Amounts in thousands)
Assets
Investments	$	3,732,728	$	3,547,560
Note receivable	5,565		—
Total return swaps	—		667
Liabilities
Total return swaps	1,200		765
Options sold	123		20
Secured notes	—		140,000
Unsecured notes	385,583		180,000