Fair value measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Available-for-sale securities

Details of available-for-sale securities were as follows:

December 31, 2019	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Mortgage-backed securities	$	9,804	$	87	$	10	$	9,881
U.S. Treasury securities	1,228		1		—		1,229
Total	$	11,032	$	88	$	10	$	11,110

December 31, 2018	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Mortgage-backed securities	$	10,473	$	21	$	162	$	10,332
U.S. Treasury securities	179		—		—		179
Total	$	10,652	$	21	$	162	$	10,511

Assets and liabilities measured at fair value on a recurring basis

The Company's assets measured at fair value on a recurring basis were as follows:

	Fair Value Measurements at December 31, 2019, Using
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs  (Level 3)		Balance at December 31, 2019
	(In thousands)
Assets:
Money market funds	$	—	$	8,440	$	—	$	8,440
Insurance contract*	—		87,009		—		87,009
Available-for-sale securities:
Mortgage-backed securities	—		9,881		—		9,881
U.S. Treasury securities	—		1,229		—		1,229
Total assets measured at fair value	$	—	$	106,559	$	—	$	106,559

* The insurance contract invests approximately 51 percent in fixed-income investments, 23 percent in common stock of large-cap companies, 12 percent in common stock of mid-cap companies, 10 percent in common stock of small-cap companies, 3 percent in target date investments and 1 percent in cash equivalents.

	Fair Value Measurements at December 31, 2018, Using
	Quoted Prices in Active Markets for Identical Assets  (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs  (Level 3)		Balance at December 31, 2018
	(In thousands)
Assets:
Money market funds	$	—	$	10,799	$	—	$	10,799
Insurance contract*	—		73,838		—		73,838
Available-for-sale securities:
Mortgage-backed securities	—		10,332		—		10,332
U.S. Treasury securities	—		179		—		179
Total assets measured at fair value	$	—	$	95,148	$	—	$	95,148

* The insurance contract invests approximately 53 percent in fixed-income investments, 21 percent in common stock of large-cap companies, 11 percent in common stock of mid-cap companies, 10 percent in common stock of small-cap companies, 3 percent in target date investments and 2 percent in cash equivalents.

Fair value of long-term debt outstanding

The estimated fair value of the Company's Level 2 long-term debt at December 31 was as follows:

	2019		2018
	(In thousands)
Carrying Amount	$	2,243,107	$	2,108,695
Fair Value	$	2,418,631	$	2,183,819