Disclosures about Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Summary of Company's Financial Instruments Whose Carrying Amount Did Not Equal Fair Value

A summary of our financial instruments whose carrying value did not equal fair value is shown below:

	December 31,
	2019				2018
(in millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Junior subordinated debentures:
Trust preferred debentures	$	172.7	$	174.0	$	172.7	$	163.2
Subordinated debentures	84.7		92.5		84.3		85.0
Total junior subordinated debentures	257.4		266.5		257.0		248.2
Senior unsecured fixed rate notes	140.0		144.2		139.8		139.5
Floating rate loan stock	56.3		56.8		57.8		54.5

Based on an analysis of the inputs, our financial instruments measured at fair value on a recurring basis have been categorized as follows:

			Fair Value Measurements at Reporting Date Using
(in millions)	December 31, 2019		Level 1 (a)		Level 2 (b)		Level 3 (c)
Junior subordinated debentures:
Trust preferred debentures	$	174.0	$	—	$	174.0	$	—
Subordinated debentures	92.5		—		92.5		—
Total junior subordinated debentures	266.5		—		266.5		—
Senior unsecured fixed rate notes	144.2		144.2		—		—
Floating rate loan stock	56.8		—		56.8		—
	467.5		144.2		323.3		—

^(a)  Quoted prices in active markets for identical assets

^(b)  Significant other observable inputs

^(c)  Significant unobservable inputs

			Fair Value Measurements at Reporting Date Using
(in millions)	December 31, 2018		Level 1 (a)		Level 2 (b)		Level 3 (c)
Junior subordinated debentures:
Trust preferred debentures	$	163.2	$	—	$	163.2	$	—
Subordinated debentures	85.0		—		85.0		—
Total junior subordinated debentures	248.2		—		248.2		—
Senior unsecured fixed rate notes	139.5		139.5		—		—
Floating rate loan stock	54.5		—		54.5		—
	442.2		139.5		302.7		—

^(a)  Quoted prices in active markets for identical assets

^(b)  Significant other observable inputs

^(c) 

Significant unobservable inputs