Long-Term Debt (Senior Notes Due 2022) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended
	Jul. 17, 2012	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2012
Debt Instrument [Line Items]
Stated interest rate		6.50%
Senior notes, minimum debt amount guaranteed by subsidiaries		$ 5,000
3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Senior notes, principal amount issued	250,000
Stated interest rate	3.60%	3.60%	3.60%	3.60%
Maturity	2022	2022
Senior notes, original discount issue	1,183
Senior notes, repurchase price as percentage of principal amount upon change of control and below investment grade rating event	101.00%
Senior notes, maximum number of days from change of control for below investment grade rating event	60 days
Senior notes, minimum debt amount guaranteed by subsidiaries		$ 5,000		$ 5,000
Prior to April Fifteenth Twenty Twenty Two | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Senior notes, redemption price as percentage of principal amount		100.00%
On or After April Fifteenth Twenty Twenty Two | 3.60% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Senior notes, redemption price as percentage of principal amount		100.00%