Earnings per Share Earnings per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted average common shares—basic	45,435,936	45,157,412	45,381,592	45,102,067
Weighted average common shares—diluted	45,760,455	45,499,104	45,713,873	45,439,618
Restricted Shares [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Incremental common shares attributable to share-based payment arrangements	244,757	216,642	248,942	218,949
Stock Options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Incremental common shares attributable to share-based payment arrangements	79,762	125,050	83,339	118,602