Segment financial information (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of segment financial information

Segment financial information was as follows:

(in thousands)	Electric utility		Bank		Other			Total
2015
Revenues from external customers	$	2,335,135	$	267,733	$	114		$	2,602,982
Intersegment revenues (eliminations)	31		—		(31		)	—
Revenues	2,335,166		267,733		83			2,602,982
Depreciation and amortization	186,319		7,928		1,338			195,585
Interest expense, net	66,370		11,326		10,780			88,476
Income (loss) before income taxes	217,131		83,812		(46,155		)	254,788
Income taxes (benefit)	79,422		29,082		(15,483		)	93,021
Net income (loss)	137,709		54,730		(30,672		)	161,767
Preferred stock dividends of subsidiaries	1,995		—		(105		)	1,890
Net income (loss) for common stock	135,714		54,730		(30,567		)	159,877
Capital expenditures	350,161		13,470		173			363,804
Assets (at December 31, 2015)	5,680,054		6,014,755		95,387			11,790,196
2014
Revenues from external customers	$	2,987,299	$	252,497	$	(254	)	$	3,239,542
Intersegment revenues (eliminations)	24		—		(24		)	—
Revenues	2,987,323		252,497		(278		)	3,239,542
Depreciation and amortization	176,284		5,399		1,361			183,044
Interest expense, net	64,757		10,808		11,595			87,160
Income (loss) before income taxes	220,361		79,295		(34,058		)	265,598
Income taxes (benefit)	80,725		27,994		(13,140		)	95,579
Net income (loss)	139,636		51,301		(20,918		)	170,019
Preferred stock dividends of subsidiaries	1,995		—		(105		)	1,890
Net income (loss) for common stock	137,641		51,301		(20,813		)	168,129
Capital expenditures	336,679		28,073		74			364,826
Assets (at December 31, 2014)	5,557,542		5,566,222		61,378			11,185,142
2013
Revenues from external customers	$	2,980,139	$	258,147	$	184		$	3,238,470
Intersegment revenues (eliminations)	33		—		(33		)	—
Revenues	2,980,172		258,147		151			3,238,470
Depreciation and amortization	161,759		4,230		1,396			167,385
Interest expense, net	59,279		10,077		16,200			85,556
Income (loss) before income taxes	194,041		89,148		(33,353		)	249,836
Income taxes (benefit)	69,117		31,421		(14,301		)	86,237
Net income (loss)	124,924		57,727		(19,052		)	163,599
Preferred stock dividends of subsidiaries	1,995		—		(105		)	1,890
Net income (loss) for common stock	122,929		57,727		(18,947		)	161,709
Capital expenditures	378,044		11,193		201			389,438
Assets (at December 31, 2013)	5,066,427		5,244,686		29,793			10,340,906