Long-Term Investments (Tables)

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Summary of Available-for-Sale Securities

The following is a summary of the available-for-sale security (in thousands):

December 31, 2019	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Failed Auction Security	$	3,000	$	—	$	490	$	2,510
December 31, 2018
Failed Auction Security	$	3,000	$	—	$	474	$	2,526

Cost and Estimated Fair Value of Failed Auction Security by Contractual Maturities

The amortized cost and estimated fair value of the available-for-sale security on December 31, 2019, by contractual maturities, are shown below (in thousands):

	Cost		Estimated Fair Value
Due in twenty to forty years	$	3,000	$	2,510

Rollforward of Credit (Gain) Loss Recognized in Earnings on Failed Auction Security

The following table represents a rollforward of the activity related to the credit loss recognized in earnings on the available-for-sale auction rate security held by the Company for the years ended December 31 (in thousands):

	2019			2018			2017
Balance at the beginning of the period	$	41		$	48		$	59
Reductions in the amount related to credit gain for which other-than-temporary impairment was not previously recognized		(4	)		(7	)		(11	)
Balance at the end of the period	$	37		$	41		$	48