Financial Instruments and Credit Risk (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Carrying Amount and Estimated Fair Value of Financial Instruments

The following tables present the carrying amount and estimated fair value as of December 31, 2015 and 2014 of our financial instruments recognized at fair value on a recurring basis:

	December 31, 2015
			Estimated Fair Value Measurements
			Quoted		Significant
			Prices in		Other		Significant
			Active		Observable		Unobservable
	Carrying		Markets		Inputs		Inputs
	Amount		(Level 1)		(Level 2)		(Level 3)
Assets—
Marketable securities	$	6,352	$	6,352	$	—	$	—

	December 31, 2014
			Estimated Fair Value Measurements
			Quoted		Significant
			Prices in		Other		Significant
			Active		Observable		Unobservable
	Carrying		Markets		Inputs		Inputs
	Amount		(Level 1)		(Level 2)		(Level 3)
Assets—
Marketable securities	$	6,175	$	6,175	$	—	$	—