Stockholders' Equity and Earnings Per Common Share (Tables)

12 Months Ended

Dec. 31, 2018

Stockholders' Equity and Earnings Per Common Share [Abstract]

Schedule of Basic and Diluted Earnings Per Share

Net income per common share is determined as follows:

	Year Ended December 31
	2018		2017		2016
	(in millions of dollars, except share data)
Numerator
Net Income	$	523.4	$	994.2	$	931.4
Denominator (000s)
Weighted Average Common Shares - Basic	219,635.6		226,492.4		235,445.7
Dilution for Assumed Exercises of Stock Options and Nonvested Stock Awards	423.0		842.8		533.5
Weighted Average Common Shares - Assuming Dilution	220,058.6		227,335.2		235,979.2
Net Income Per Common Share
Basic	$	2.38	$	4.39	$	3.96
Assuming Dilution	$	2.38	$	4.37	$	3.95

Treasury Stock Transactions

Our board of directors has authorized the repurchase of Unum Group's common stock under the following repurchase programs:

	Share Repurchase Program Authorized During
	May 2018		May 2017		May 2016
	(in millions of dollars)
Authorized Repurchase Amount	$	750.0	$	750.0	$	750.0
Remaining Repurchase Amount at Year End 2018	$	500.0	$	—	$	—

The May 2018 share repurchase program has an expiration date of November 24, 2019.

Common stock repurchases, which are accounted for using the cost method and classified as treasury stock until otherwise retired, were as follows:

	Year Ended December 31
	2018		2017		2016
	(in millions)
Shares Repurchased	8.7		8.2		11.9
Cost of Shares Repurchased (1)	$	350.7	$	400.4	$	403.3

(1) Includes commissions of $0.7 million, $0.3 million, and $0.2 million for the years ended December 31, 2018, 2017, and 2016, respectively.