Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Summary of Placement in the Fair Value Hierarchy of Financial Assets that are Measured at Fair Value on a Recurring Basis

The following table presents the placement in the fair value hierarchy of financial assets that are measured at fair value on a recurring basis, including the items for which the fair value option has been elected, at March 31, 2018:

	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		March 31, 2018
Assets
Equity securities	9,622		4,421		—		14,043
Preferred stock	—		—		166,069		166,069
Other	—		769		—		769
Total	$	9,622	$	5,190	$	166,069	$	180,881

The following table presents the placement in the fair value hierarchy of financial assets that are measured at fair value on a recurring basis, including the items for which the fair value option has been elected, at December 31, 2017:

	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		December 31, 2017
Assets
U.S. government debt securities	$	—	$	5,998	$	—	$	5,998
Equity securities	10,537		4,563		—		15,100
Preferred stock	—		—		161,225		161,225
Other	—		850		—		850
Total	$	10,537	$	11,411	$	161,225	$	183,173