Subsequent Events (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended	1 Months Ended		3 Months Ended	1 Months Ended
	Feb. 28, 2013	Mar. 31, 2013	May 07, 2013 Subsequent Event [Member]	Apr. 30, 2013 Subsequent Event [Member]	Mar. 31, 2013 Subsequent Event [Member]	Apr. 30, 2013 Subsequent Event [Member] Maximum [Member]	Apr. 30, 2013 Subsequent Event [Member] Minimum [Member]
Subsequent Events (Textual) [Abstract]
Repurchase of common stock	$ 50.0	$ 360.0		$ 130.0
Common stock repurchase price						$ 36.00	$ 32.00
Increments per share				$ 0.25
Tender offer expiry date					May 01, 2013
Common stock purchase			2,054,732
Stock repurchased during period per share amount			$ 36.00
Stock repurchased during period value			$ 74.0