Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2018

Equity [Abstract]

Schedule of Repurchase of Shares

A summary of common shares repurchased for the six months ended June 30, 2018 is shown below:

Repurchase Type	Date Trading Plan Initiated	2018 Purchase Period	Number of Shares Repurchased	Average Price of Shares Repurchased		Total Cost (in millions)		Repurchase Authorization Year
10b5-1 Trading Plan	12/15/2017	01/02/2018-02/16/2018	225,281	$	59.31	$	13.3	2016
10b5-1 Trading Plan	6/15/2018	06/22/2018-06/29/2018	29,947	$	58.86	1.8		2016
Open Market	N/A	02/20/2018-03/02/2018	89,305	$	59.03	5.3		2016
Total			344,533	$	59.20	$	20.4