Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Measurements [Abstract]

Fair Value Measurements on a Recurring Basis

March 31, 2018

	Carrying amount				Fair Value Measurement Using
	in balance sheet		Fair Value		Level 1		Level 2		Level 3
Assets:
Cash equivalents
Commercial paper	$	346	$	346	$	346	$	0	$	0
Treasury bills		7,705		7,705		7,705		0		0
Equity Securities		45		45		0		0		45

December 31, 2017

	Carrying amount				Fair Value Measurement Using
	in balance sheet		Fair Value		Level 1		Level 2		Level 3
Assets:
Cash equivalents
Commercial paper	$	568	$	568	$	568	$	0	$	0
Treasury bills		7,711		7,711		7,711		0		0
Equity Securities		45		45		0		0		45
Liabilities:
Contingent earn-out		150		150		0		0		150

Summary of change in level 3 liabilities at fair value on a recurring basis

	Three Months Ended March 31
		2018			2017
Beginning Balance	$	150		$	195
Change in Fair Value		0			0
Payments		(150	)		0
Ending Balance	$	0		$	195