Segment financial information (Tables)

3 Months Ended

Mar. 31, 2017

Segment Reporting [Abstract]

Schedule of segment financial information

(in thousands)	Electric utility		Bank		Other			Total
Three months ended March 31, 2017
Revenues from external customers	$	518,566	$	72,856	$	140		$	591,562
Intersegment revenues (eliminations)	45		—		(45		)	—
Revenues	$	518,611	$	72,856	$	95		$	591,562
Income (loss) before income taxes	$	34,722	$	24,160	$	(7,300	)	$	51,582
Income taxes (benefit)	12,758		8,347		(4,189		)	16,916
Net income (loss)	21,964		15,813		(3,111		)	34,666
Preferred stock dividends of subsidiaries	499		—		(26		)	473
Net income (loss) for common stock	$	21,465	$	15,813	$	(3,085	)	$	34,193
Total assets (at March 31, 2017)	$	5,969,042	$	6,559,646	$	14,587		$	12,543,275
Three months ended March 31, 2016
Revenues from external customers	$	482,045	$	68,840	$	75		$	550,960
Intersegment revenues (eliminations)	7		—		(7		)	—
Revenues	$	482,052	$	68,840	$	68		$	550,960
Income (loss) before income taxes	$	40,419	$	19,594	$	(8,887	)	$	51,126
Income taxes (benefit)	14,553		6,921		(3,173		)	18,301
Net income (loss)	25,866		12,673		(5,714		)	32,825
Preferred stock dividends of subsidiaries	499		—		(26		)	473
Net income (loss) for common stock	$	25,367	$	12,673	$	(5,688	)	$	32,352
Total assets (at December 31, 2016)	$	5,975,428	$	6,421,357	$	28,721		$	12,425,506