Floating Rate Capital Debt (Tables)

12 Months Ended

Dec. 31, 2017

Brokers and Dealers [Abstract]

Summary of Book Values of Outstanding Subordinated Debentures

The following table summarizes the book values of the outstanding subordinated debentures as of December 31, 2017 and 2016.

TABLE 77: SUBORDINATED DEBENTURES

	DECEMBER 31,
(In Millions)	2017		2016
NTC Capital I Subordinated Debentures due January 15, 2027	$	154.2	$	154.1
NTC Capital II Subordinated Debentures due April 15, 2027	123.3		123.3
Total Subordinated Debentures	$	277.5	$	277.4