Summary of Significant Accounting Policies (Basic and Diluted Earnings Per Share (in shares)) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Weighted-average shares for basic EPS	139,486,936	139,287,231	139,359,798	138,949,907
Plus incremental shares related to stock options and non-vested restricted stock	25,038	140,692	176,819	266,567
Weighted-average shares for diluted EPS	139,511,974	139,427,923	139,536,617	139,216,474