Earnings per common share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Computations of Basic Earnings Per Common Share

The computations of basic earnings per common share follow:

	Year Ended December 31
	2016			2015			2014
	(In thousands, except per share)
Income available to common shareholders:
Net income	$	1,315,114		$	1,079,667		$	1,066,246
Less: Preferred stock dividends(a)		(81,270	)		(81,270	)		(75,878	)
Net income available to common equity		1,233,844			998,397			990,368
Less: Income attributable to unvested stock-based    compensation awards		(10,385	)		(10,708	)		(11,837	)
Net income available to common shareholders	$	1,223,459		$	987,689		$	978,531
Weighted-average shares outstanding:
Common shares outstanding (including common stock    issuable) and unvested stock-based compensation    awards		158,121			138,285			132,532
Less: Unvested stock-based compensation awards		(1,341	)		(1,482	)		(1,582	)
Weighted-average shares outstanding		156,780			136,803			130,950
Basic earnings per common share	$	7.80		$	7.22		$	7.47

(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:

	Year Ended December 31
	2016			2015			2014
	(In thousands, except per share)
Net income available to common equity	$	1,233,844		$	998,397		$	990,368
Less: Income attributable to unvested stock-based    compensation awards		(10,363	)		(10,673	)		(11,787	)
Net income available to common shareholders	$	1,223,481		$	987,724		$	978,581
Adjusted weighted-average shares outstanding:
Common and unvested stock-based compensation    awards		158,121			138,285			132,532
Less: Unvested stock-based compensation awards		(1,341	)		(1,482	)		(1,582	)
Plus: Incremental shares from assumed conversion of    stock-based compensation awards and warrants to    purchase common stock		524			730			894
Adjusted weighted-average shares outstanding		157,304			137,533			131,844
Diluted earnings per common share	$	7.78		$	7.18		$	7.42