Shareholders' Equity - Summary of Common Shares Outstanding (Details 3) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Roll forward of common shares outstanding
Balance at the beginning of the year, shares	33,392,060	33,558,864
Repurchases, shares	(984,382)	(460,496)
Stock option issuances, shares	5,200	101,350
Restricted share issuances, shares	135,599	192,342
Balance at the end of the period, shares	32,548,477	33,392,060