Earnings per common share (Tables)

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Abstract]

Computations of Basic Earnings Per Common Share

The computations of basic earnings per common share follow:

	Three months ended March 31
	2013			2012
	(in thousands, except per share)
Income available to common shareholders:
Net income	$	274,113			206,463
Less: Preferred stock dividends (a)		(13,363	)		(13,363	)
Amortization of preferred stock discount (a)		(2,147	)		(1,924	)
Net income available to common equity		258,603			191,176
Less: Income attributable to unvested stock-based compensation awards		(3,524	)		(2,940	)
Net income available to common shareholders	$	255,079			188,236
Weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards		129,449			127,157
Less: Unvested stock-based compensation awards		(1,780	)		(1,937	)
Weighted-average shares outstanding		127,669			125,220
Basic earnings per common share	$	2.00			1.50

(a) Including impact of not as yet declared cumulative dividends.

Computations of Diluted Earnings Per Common Share

The computations of diluted earnings per common share follow:

	Three months ended March 31
	2013			2012
	(in thousands, except per share)
Net income available to common equity	$	258,603			191,176
Less: Income attributable to unvested stock-based compensation awards		(3,507	)		(2,935	)
Net income available to common shareholders	$	255,096			188,241
Adjusted weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards		129,449			127,157
Less: Unvested stock-based compensation awards		(1,780	)		(1,937	)
Plus: Incremental shares from assumed conversion of stock-based compensation awards and convertible preferred stock		967			396
Adjusted weighted-average shares outstanding		128,636			125,616
Diluted earnings per common share	$	1.98			1.50