Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Schedule of Repurchase of Shares

A summary of common shares repurchased for the twelve months ended December 31, 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	12/18/2017	01/02/2018-02/16/2018	225,281	$	59.31	$	13.3	2016
10b5-1 Trading Plan	6/18/2018	06/22/2018- 08/07/2018	75,661	$	59.30	4.5		2016
10b5-1 Trading Plan	9/18/2018	09/19/2018-10/24/2018	37,385	$	59.75	2.2		2016
Open Market	N/A	02/20/2018-03/02/2018	89,305	$	59.03	5.3		2016
Open Market	N/A	08/13/2018-09/17/2018	103,250	$	62.07	6.4		2016
Total			530,882	$	59.83	$	31.7