Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Comprehensive income:
Net unrealized gains on available-for-sale securities, tax benefit	$ (6.7)	$ 0
Cash flow hedges, tax provision	31.4	34.3
Postretirement plans and workers' compensation obligations, tax provision	$ 8.1	$ 0.2

Tax effects of the increase (decrease) to accumulated comprehensive income during the period related to benefit plans. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

Total tax effect of the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. The change includes an entity's share of an equity investee's increase or decrease in deferred hedging gains or losses. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

Tax effect on gross appreciation or the gross loss in value of the total of unsold securities during the period being reported on.

+ References+ Details