Common Shares (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		9 Months Ended		12 Months Ended
	Jul. 29, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Common Shares
Shares repurchased		0.3
Repurchase of treasury shares		$ 1,687	$ 78,399
Common shares
Common stock dividend declared (in dollars per share)	$ 0.06	$ 0.06		$ 0.06
Cash dividends paid		$ 33,927	$ 52,489