Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Stockholders' Equity Note [Abstract]

Preferred shares

At December 31, 2019 and 2018, the Company's issued and outstanding redeemable preferred shares, each with a par value of $1.00 per share, were as follows (in millions of U.S. dollars, except number of shares and percentage amounts):

	Series F			Series G			Series H			Series I			Total
Date of issuance	February 2013			May 2016			May 2016			May 2016
Number of preferred shares outstanding	2,679,426			6,415,264			11,753,798			7,320,574			28,169,062
Annual dividend rate	5.875		%	6.5		%	7.25		%	5.875		%
Underwriting discounts and commissions(1)	$	2.3		$	5.4		$	9.5		$	6.4		$	23.6
Aggregate liquidation value, at $25 per share	$	67.0		$	160.4		$	293.8		$	183.0		$	704.2

(1) Underwriting discounts and commissions represent the original amounts paid to issue Series D, E and F shares. These amounts were reallocated on a pro-rata basis between the previously issued and the newly issued shares as a result of the share exchange in May 2016 for $nil consideration described below.