Shareholders' Equity (Tables)

9 Months Ended

Sep. 30, 2017

Stockholders' Equity Note [Abstract]

Summary of dividends declared and paid per share

The following table provides a summary of dividends declared and paid per share:

	Nine Months Ended September 30,
	2017				2016
	Declared		Paid		Declared		Paid
Common shares	$	2.960	$	2.940	$	2.860	$	2.820
5.417% Series 1 Cumulative Convertible Preferred shares	$	1.016	$	1.016	$	1.016	$	1.016