Supplemental Statements of Cash Flows Disclosures (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Information [Abstract]

Schedule of Cash Flow, Supplemental Disclosures

	Years Ended December 31,
	2017			2016		2015
	(In thousands)
Cash paid for:
Interest on long-term debt and borrowing under the revolving credit facility	$	70,523		$	69,990	$	62,297
Income tax paid, net	2,055			2,328		1,000
Non-cash investing and financing activities:
Sale of interest in Four Corners Generating Station (a)	—			27,720		—
Changes in accrued plant additions	(5,090		)	4,789		(6,660		)
Grants of restricted shares of common stock	1,171			1,235		1,567
Issuance of performance shares	932			—		—

(a) The Company sold its interest in Four Corners in July 2016. The sales proceeds were reduced by the settlement of other obligations between the Company and APS and its affiliate, 4C Acquisition, LLC. See Part II, Item 8, Financial Statements and Supplementary Data, Note E.