Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions					3 Months Ended	9 Months Ended	12 Months Ended
	Nov. 03, 2015	Aug. 03, 2015	May. 06, 2015	Feb. 10, 2015	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2012
Class of Stock [Line Items]
Stock Repurchased							2,100,000
Treasury Stock, Value, Acquired, Cost Method							$ 58.6
Dividend amount to be paid, per common share	$ 0.3150	$ 0.3075	$ 0.3000	$ 0.2925
Dividend, declaration date	Nov. 03, 2015	Aug. 03, 2015	May 06, 2015	Feb. 10, 2015
Dividend, date to be paid	Dec. 03, 2015	Sep. 01, 2015	Jun. 03, 2015	Mar. 09, 2015
Dividend, date of record	Nov. 17, 2015	Aug. 17, 2015	May 19, 2015	Feb. 23, 2015
Shares Paid for Tax Withholding for Share Based Compensation					11,730
2012 Repurchase Program [Member]
Class of Stock [Line Items]
Maximum number of shares authorized to be repurchased					5,000,000	5,000,000
Stock Repurchased						0