Share Information - Earnings Per Share Calculation (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Weighted average number of common shares used for basic EPS (in shares)	34,986,905	36,468,374	35,237,742	36,886,777
Effect of dilutive stock options and restricted and deferred stock unit awards (in shares)	479,860	314,797	0	266,394
Weighted average number of common shares and dilutive potential common stock used in dilutive EPS (in shares)	35,466,765	36,783,171	35,237,742	37,153,171