Equity, Other Comprehensive Income, Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Available-for-sale securities:
Change in unrealized gains (losses) on available- for-sale securities, Gross amount	$ 9.7		$ 9.6
Change in unrealized gains (losses) on available- for-sale securities, Tax	(3.9)		(4.0)
Change in unrealized gains (losses) on available-for-sale securities	5.8	(1.0)	5.6	2.1
Reclassification adjustment for realized net gains on available-for-sale securities included in net income, Gross amount	(0.2)		(0.7)
Reclassification adjustment for realized net gains on available-for-sale securities included in net income, Tax	0.1		0.2
Reclassification adjustment for realized net gains on available-for-sale securities included in net income	(0.1)	(0.2)	(0.5)	(0.5)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Gross Amount	9.5		8.9
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Tax	(3.8)		(3.8)
Net change in unrealized gains (losses) on available-for-sale securities	5.7	(1.2)	5.1	1.6
Cash flow hedges:
Change in unrealized (losses) gains on cash flow hedges, Gross amount	(1.7)		(3.8)
Change in unrealized (losses) gains on cash flow hedges, Tax	1.6		1.6
Change in unrealized (losses) gains on cash flow hedges	(0.1)	(3.4)	(2.2)	2.6
Reclassification adjustment for realized net (gains) losses on cash flow hedges included in net income, Gross amount	(0.6)		(2.0)
Reclassification adjustment for realized net (gains) losses on cash flow hedges included in net income, Tax	0.2		0.2
Reclassification adjustment for realized net (gains) losses on cash flow hedges included in net income	(0.4)	1.5	(1.8)	5.0
Net change in unrealized (losses) gains on cash flow hedges, Gross amount	(2.3)		(5.8)
Net change in unrealized (losses) gains on cash flow hedges, Tax	1.8		1.8
Net change in unrealized (losses) gains on cash flow hedges	(0.5)	(1.9)	(4.0)	7.6
Change in foreign currency translation adjustments, Gross amount	(3.7)		(9.5)
Change in foreign currency translation adjustments, Tax	0		0
Change in foreign currency translation adjustments	(3.7)	(4.5)	(9.5)	0.1
Other comprehensive income (soss), Gross amount	3.5		(6.4)
Other comprehensive income (loss), Tax	(2.0)		(2.0)
Other comprehensive income (loss), net of tax	$ 1.5	$ (7.6)	$ (8.4)	$ 9.3