Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Carrying Amount and Estimated Fair Value of Financial Instruments

The following tables present the carrying amount and estimated fair value of our financial instruments recognized at fair value on a recurring basis:

	December 31, 2018
			Estimated Fair Value Measurements
	Carrying Amount		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets -
Marketable securities	$	8,659	$	8,659	$	—	$	—

	December 31, 2017
			Estimated Fair Value Measurements
	Carrying Amount		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets -
Marketable securities	$	7,321	$	7,321	$	—	$	—