Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2015

Stockholders' Equity Note [Abstract]

Total Authorized Shares Table [Text Block]

At December 31, 2015 and 2014, the total authorized shares of the Company were 200 million shares, par value $1.00 per share, as follows (in millions of shares):

	Shares
Designated common shares	100.0
Designated 6.5% Series D cumulative redeemable preferred shares	9.2
Designated 7.25% Series E cumulative redeemable preferred shares	17.0
Designated 5.875% Series F non-cumulative redeemable preferred shares	14.0
Designated and redeemed preference shares	26.0
Undesignated	33.8
	200.0

Preferred Stock [Table Text Block]

During the years ended December 31, 2015, 2014 and 2013, the Company had Series C, Series D and Series E cumulative redeemable preferred shares and Series F non-cumulative redeemable preferred shares outstanding as follows (in millions of U.S. dollars or shares, except percentage amounts):

	Series C			Series D			Series E			Series F
Date of issuance	May 2003			November 2004			June 2011			February 2013
Number of preferred shares issued	11.6			9.2			15.0			10.0
Annual dividend rate	6.75		%	6.5		%	7.25		%	5.875		%
Total consideration	$	280.9		$	222.3		$	361.7		$	242.3
Underwriting discounts and commissions	$	9.1		$	7.7		$	12.1		$	7.7
Aggregate liquidation value	$	290.0		$	230.0		$	373.8		$	250.0
Date of redemption	March 2013			n/a			n/a			n/a

n/a: Not applicable