Shareholders' Equity - Summary of Common Shares Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Roll forward of common shares outstanding
Balance at the beginning of the year	32,938,466	32,762,494
Restricted share issuances	79,304	88,225
Balance at the end of the period	33,017,770	32,850,719