Stockholders' Equity and Earnings Per Common Share (Tables)

12 Months Ended

Dec. 31, 2016

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
	2016		2015		2014
	(in millions of dollars, except share data)
Numerator
Net Income	$	931.4	$	867.1	$	402.1
Denominator (000s)
Weighted Average Common Shares - Basic	235,445.7		246,986.7		255,525.9
Dilution for Assumed Exercises of Stock Options and Nonvested Stock Awards	533.5		868.0		1,126.9
Weighted Average Common Shares - Assuming Dilution	235,979.2		247,854.7		256,652.8
Net Income Per Common Share
Basic	$	3.96	$	3.51	$	1.57
Assuming Dilution	$	3.95	$	3.50	$	1.57

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 2016		May 2015		December 2013
	(in millions of dollars)
Authorized Repurchase Amount	$	750.0	$	750.0	$	750.0
Remaining Repurchase Amount at Year End 2016	$	495.7	$	—	$	—

The May 2016 share repurchase program has an expiration date of November 26, 2017.

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
	2016		2015		2014
	(in millions)
Shares Repurchased	11.9		12.3		8.7
Cost of Shares Repurchased (1)	$	403.3	$	426.7	$	300.6

(1) Includes commissions of $0.2 million, $0.3 million, and $0.1 million for the years ended December 31, 2016, 2015, and 2014, respectively.