SEGMENTS OF BUSINESS (Tables)

12 Months Ended

Dec. 31, 2014

Segment Reporting [Abstract]

Schedule of information related to reportable segments

The table below presents information related to our reportable segments:

	Regulated Utilities
2014 (Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Income Statement
External revenues	$	1,222.4		$	459.9		$	1,682.3		$	—	$	—		$	1,682.3
Intersegment revenues	—			12.4			12.4			1.4		(13.8		)	—
Depreciation and amortization expense	97.4			16.2			113.6			0.6		(0.5		)	113.7
Miscellaneous income	11.1			0.4			11.5			12.9		—			24.4
Interest expense	45.1			10.2			55.3			2.1		—			57.4
Provision for income taxes	64.1			16.6			80.7			4.0		—			84.7
Preferred stock dividend requirements	(2.6		)	(0.5		)	(3.1		)	—		—			(3.1		)
Net income attributed to common shareholder	104.7			25.7			130.4			7.2		—			137.6
Total assets	3,511.0			682.3			4,193.3			85.4		—			4,278.7
Cash expenditures for long-lived assets	279.3			49.8			329.1			—		—			329.1
	Regulated Utilities
2013 (Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Income Statement
External revenues	$	1,241.8		$	337.5		$	1,579.3		$	—	$	—		$	1,579.3
Intersegment revenues	—			10.9			10.9			1.4		(12.3		)	—
Depreciation and amortization expense	90.5			15.6			106.1			0.6		(0.5		)	106.2
Miscellaneous income	9.9			0.2			10.1			13.4		—			23.5
Interest expense	33.0			8.5			41.5			2.2		—			43.7
Provision for income taxes	61.6			16.1			77.7			4.2		—			81.9
Preferred stock dividend requirements	(2.5		)	(0.6		)	(3.1		)	—		—			(3.1		)
Net income attributed to common shareholder	102.3			25.0			127.3			7.5		—			134.8
Total assets	3,241.8			633.8			3,875.6			85.7		—			3,961.3
Cash expenditures for long-lived assets	595.5			37.7			633.2			—		—			633.2
	Regulated Utilities
2012 (Millions)	Electric Utility			Natural Gas Utility			Total Utility			Other		Reconciling Eliminations			WPS Consolidated
Income Statement
External revenues	$	1,212.0		$	287.2		$	1,499.2		$	—	$	—		$	1,499.2
Intersegment revenues	—			9.2			9.2			1.4		(10.6		)	—
Depreciation and amortization expense	81.1			15.0			96.1			0.6		(0.5		)	96.2
Miscellaneous income	2.6			0.1			2.7			13.0		—			15.7
Interest expense	32.4			7.9			40.3			2.2		—			42.5
Provision for income taxes	44.6			14.5			59.1			3.5		—			62.6
Preferred stock dividend requirements	(2.5		)	(0.6		)	(3.1		)	—		—			(3.1		)
Net income attributed to common shareholder	99.1			24.9			124.0			7.7		—			131.7
Total assets	2,747.5			668.2			3,415.7			106.2		—			3,521.9
Cash expenditures for long-lived assets	149.4			30.1			179.5			—		—			179.5