Earnings per Common Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Net Income, Weighted Average Common Shares Used In Calculating Basic Earnings Per Common Share And Diluted EPS

The following table presents net income, the weighted average common shares used in calculating basic earnings per common share ("EPS") and those used in calculating diluted EPS for each period presented below.

	Years Ended December 31,
	2016			2015			2014
Numerator
Net income	$	565,350		$	141,555		$	470,907
Deduct dividends paid	(125,346		)	(94,168		)	(77,495		)
Undistributed earnings	$	440,004		$	47,387		$	393,412
Denominator
Weighted average shares outstanding used in basic earnings per share   calculations	61,261,288			68,163,825			72,181,447
Incremental common shares from:
PSUs	632,731			789,547			905,648
ESPP	40,755			63,837			64,915
Weighted average shares used in diluted earnings per share calculations	61,934,774			69,017,209			73,152,010
Earnings per common share – Basic
Distributed earnings	$	2.05		$	1.38		$	1.06
Undistributed earnings	7.18			0.70			5.46
Net income	$	9.23		$	2.08		$	6.52
Earnings per common share – Diluted
Distributed earnings	$	2.03		$	1.36		$	1.06
Undistributed earnings	7.10			0.69			5.38
Net income	$	9.13		$	2.05		$	6.44