XML 26 R32.htm IDEA: XBRL DOCUMENT

Accounting for Stock-Based Compensation - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of discounted closing price for Employee Stock Purchase Plan			85.00%
Long Term Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation	$ 6.0	$ 6.4	$ 17.9	$ 18.7
Unrecognized compensation cost	$ 31.1		$ 31.1

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References+ Details