Segment financial information (Tables)

9 Months Ended

Sep. 30, 2017

Segment Reporting [Abstract]

Schedule of segment financial information

(in thousands)	Electric utility		Bank		Other			Total
Three months ended September 30, 2017
Revenues from external customers	$	598,756	$	74,289	$	140		$	673,185
Intersegment revenues (eliminations)	13		—		(13		)	—
Revenues	$	598,769	$	74,289	$	127		$	673,185
Income (loss) before income taxes	$	74,990	$	26,764	$	(6,615	)	$	95,139
Income taxes (benefit)	27,005		9,172		(1,582		)	34,595
Net income (loss)	47,985		17,592		(5,033		)	60,544
Preferred stock dividends of subsidiaries	498		—		(27		)	471
Net income (loss) for common stock	$	47,487	$	17,592	$	(5,006	)	$	60,073
Nine months ended September 30, 2017
Revenues from external customers	$	1,674,158	$	222,474	$	396		$	1,897,028
Intersegment revenues (eliminations)	97		—		(97		)	—
Revenues	$	1,674,255	$	222,474	$	299		$	1,897,028
Income (loss) before income taxes	$	150,715	$	75,720	$	(20,088	)	$	206,347
Income taxes (benefit)	54,623		25,582		(8,202		)	72,003
Net income (loss)	96,092		50,138		(11,886		)	134,344
Preferred stock dividends of subsidiaries	1,496		—		(79		)	1,417
Net income (loss) for common stock	$	94,596	$	50,138	$	(11,807	)	$	132,927
Total assets (at September 30, 2017)	$	6,107,501	$	6,618,907	$	16,442		$	12,742,850
Three months ended September 30, 2016
Revenues from external customers	$	572,208	$	73,708	$	139		$	646,055
Intersegment revenues (eliminations)	45		—		(45		)	—
Revenues	$	572,253	$	73,708	$	94		$	646,055
Income before income taxes	$	75,617	$	22,727	$	80,861		$	179,205
Income taxes	28,145		7,623		15,824			51,592
Net income	47,472		15,104		65,037			127,613
Preferred stock dividends of subsidiaries	498		—		(27		)	471
Net income for common stock	$	46,974	$	15,104	$	65,064		$	127,142
Nine months ended September 30, 2016
Revenues from external customers	$	1,549,602	$	213,297	$	360		$	1,763,259
Intersegment revenues (eliminations)	98		—		(98		)	—
Revenues	$	1,549,700	$	213,297	$	262		$	1,763,259
Income before income taxes	$	174,376	$	62,545	$	64,321		$	301,242
Income taxes	64,682		21,483		10,038			96,203
Net income	109,694		41,062		54,283			205,039
Preferred stock dividends of subsidiaries	1,496		—		(79		)	1,417
Net income for common stock	$	108,198	$	41,062	$	54,362		$	203,622
Total assets (at December 31, 2016)	$	5,975,428	$	6,421,357	$	28,721		$	12,425,506