Share-Based Compensation (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2012 MSU	Dec. 31, 2012 MSU item	Oct. 31, 2012 MSU Maximum	Jun. 30, 2012 PSUs	Dec. 31, 2012 PSUs
Performance-Based Awards
Number of awards granted to employees (in shares)	0.2			1.0
Total fair value of awards granted to employees	$ 1.2	$ 1.2		$ 3.9
Number of awards at the end of the period					0.7
Target number of shares that participating executives may earn (as a percent)			150.00%
Number of measurement periods		2
Weighted average period for recognition of compensation costs		2 years 1 month 6 days