Other Income, Net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Income and Expenses [Abstract]
Interest income	$ 1,761	$ 3,603	$ 4,860
Other nonoperating income	2,603	2,233	2,512
Insurance policy expense	(1,228)	(1,100)	(359)
Other Nonoperating Expense	0	0	(12)
Other income, net	$ 3,136	$ 4,736	$ 7,001