Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Aug. 07, 2015	Sep. 30, 2015	Sep. 30, 2015	Oct. 14, 2015	Feb. 03, 2015	Aug. 05, 2014
Subsequent Event [Line Items]
Stock Repurchased During Period, Shares		1,169,458
Repurchase and retirement of common stock, Value		$ (34,311)	$ (68,793)
Common Stock, Dividends, Per Share, Cash Paid		$ 29.34
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock Repurchased During Period, Shares	20,000
Repurchase and retirement of common stock, Value	$ (500)
Common Stock, Dividends, Per Share, Cash Paid	$ 24.98
Secured Syndicated Credit Facility, First Amendment [Member] | Regions Bank [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Expansion					$ 90,000
Revolving Credit Facility [Member] | Secured Syndicated Credit Facility, First Amendment [Member] | TD Bank [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Credit agreement, maximum borrowing capacity				$ 25,000
Revolving Credit Facility [Member] | Secured Syndicated Credit Facility, First Amendment [Member] | Regions Bank [Member]
Subsequent Event [Line Items]
Credit agreement, maximum borrowing capacity					$ 240,000	$ 200,000
Revolving Credit Facility [Member] | Secured Syndicated Credit Facility, First Amendment [Member] | Regions Bank [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Credit agreement, maximum borrowing capacity				240,000
Revolving Credit Facility [Member] | Secured Syndicated Credit Facility [Member] | Regions Bank [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Expansion						50,000
Credit agreement, maximum borrowing capacity						$ 200,000
Credit agreement, amount outstanding		$ 186,465	186,465
Revolving Credit Facility [Member] | Secured Syndicated Credit Facility [Member] | Regions Bank [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Expansion				$ 50,000
Credit agreement, amount outstanding		$ 186,500	$ 186,500