Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2017

Debt Disclosure [Abstract]

Schedule of Debt

(In thousands)	June 30, 2017		December 31, 2016
2006 Senior Notes payable through 2021, 5.41%, net of debt issuance costs	$	33,333	$	33,333
2010 Senior Notes payable through 2021, 4.00%, net of debt issuance costs	100,000		100,000
2016 Senior Notes payable through 2031, 3.40%, net of debt issuance costs	71,448		67,713
Senior revolving credit facility maturing in 2020, net of debt issuance costs	64,564		189,456
Total	269,345		390,502
Amounts due within one year, net of debt issuance costs	26,666		26,666
Long-term debt, net of debt issuance costs	$	242,679	$	363,836