Consolidated Statements of Changes in Stockholders Equity (Unaudited) (USD $)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock, at Cost	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2009	$ 1,433,300,000	$ 900,000	$ 1,165,700,000	$ 316,400,000	$ 0	$ (49,700,000)
Common stock issued (net of issuance costs of $20.6)	282,500,000	300,000	282,200,000
comprehensive income, net of taxes:
Net income	82,100,000			82,100,000
Other comprehensive income (net of taxes: $296.5 and $89.0, respectively)	550,800,000					550,800,000
Total comprehensive income, net of taxes	632,900,000
Stock-based compensation	1.0		1.6		(0.6)
Dividends declared	(6,900,000)			(6,900,000)
Ending Balance at Jun. 30, 2010	2,342,800,000	1,200,000	1,449,500,000	391,600,000	(600,000)	501,100,000
Beginning Balance at Dec. 31, 2010	2,380,600,000	1,200,000	1,450,200,000	496,700,000	0	432,500,000
comprehensive income, net of taxes:
Net income	114,300,000			114,300,000
Other comprehensive income (net of taxes: $296.5 and $89.0, respectively)	165,400,000					165,400,000
Total comprehensive income, net of taxes	279,700,000
Stock-based compensation	2.1		2.1
Dividends declared	(15,100,000)			(15,100,000)
Ending Balance at Jun. 30, 2011	$ 2,647,300,000	$ 1,200,000	$ 1,452,300,000	$ 595,900,000	$ 0	$ 597,900,000