Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2016

Debt Disclosure [Abstract]

Schedule of Debt

(In thousands)	June 30, 2016		December 31, 2015
2006 Senior Notes payable through 2021, 5.41%, net of debt issuance costs	$	40,000	$	39,999
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	73,028		—
Senior revolving credit facility maturing in 2020, net of debt issuance costs	240,716		324,673
Total	453,744		464,672
Amounts due within one year, net of debt issuance costs	6,657		6,650
Long-term debt, net of debt issuance costs	$	447,087	$	458,022