Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2013

Debt Disclosure [Abstract]

Outstanding Amount of Credit Facilities

Amounts outstanding under the Company’s credit facilities consist of the following:

	December 31
	2013		2012
	(In Thousands)
Unsecured revolving line of credit, $850,000,000, LIBOR plus 0.75% variable	$	264,658	$	—
Unsecured term notes:
November 30, 2008, Series C Senior Unsecured Notes, $250,000,000, 4.67% fixed, due November 30, 2013		—		250,000
November 30, 2011, Series D and E Senior Unsecured Notes, $250,000,000, 3.35% fixed, due November 30, 2016		250,000		250,000
December 2, 2013, Series F Senior Unsecured Notes, $250,000,000, 2.99% fixed, due December 2, 2023		250,000		—
Total debt		764,658		500,000
Less debt due within one year		264,658		250,000
Long-term debt, excluding current portion	$	500,000	$	250,000