Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reconciliation of number of shares used in calculation of basic and diluted earnings per share
Weighted average number of common shares outstanding	85,300,000	90,200,000	86,700,000	90,200,000
Effect of non-participatory equity compensation (in shares)	36,000	36,000	36,000	36,000
Weighted average number of common shares outstanding, including effect of dilutive securities	85,300,000	90,200,000	86,800,000	90,300,000