Note 9 - Short-term and Long-term Borrowings (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Schedule of Line of Credit Facilities [Table Text Block]

(in thousands)	Line Limit		In Use on June 30, 2018		Restricted due to Outstanding Letters of Credit		Available on June 30, 2018		Available on December 31, 2017
Otter Tail Corporation Credit Agreement	$	130,000	$	6,102	$	--	$	123,898	$	130,000
OTP Credit Agreement		170,000		14,875		300		154,825		57,329
Total	$	300,000	$	20,977	$	300	$	278,723	$	187,329

Schedule of Debt [Table Text Block]

June 30 , 2018 (in thousands)	OTP		Otter Tail Corporation		Otter Tail Corporation Consolidated
Short-Term Debt	$	14,875	$	6,102	$	20,977
Long-Term Debt:
3.55% Guaranteed Senior Notes, due December 15, 2026			$	80,000	$	80,000
Senior Unsecured Notes 4.63%, due December 1, 2021	$	140,000				140,000
Senior Unsecured Notes 6.15%, Series B, due August 20, 2022		30,000				30,000
Senior Unsecured Notes 6.37%, Series C, due August 20, 2027		42,000				42,000
Senior Unsecured Notes 4.68%, Series A, due February 27, 2029		60,000				60,000
Senior Unsecured Notes 6.47%, Series D, due August 20, 2037		50,000				50,000
Senior Unsecured Notes 5.47%, Series B, due February 27, 2044		90,000				90,000
Senior Unsecured Notes 4.07%, Series 2018A, due February 7, 2048		100,000				100,000
North Dakota Development Note, 3.95%, fully repaid April 1, 2018				--		--
PACE Note, 2.54%, due March 18, 2021				604		604
Total	$	512,000	$	80,604	$	592,604
Less: Current Maturities net of Unamortized Debt Issuance Costs		--		167		167
Unamortized Long-Term Debt Issuance Costs		2,045		432		2,477
Total Long-Term Debt net of Unamortized Debt Issuance Costs	$	509,955	$	80,005	$	589,960
Total Short-Term and Long-Term Debt (with current maturities)	$	524,830	$	86,274	$	611,104

December 31, 2017 (in thousands)	OTP		Otter Tail Corporation		Otter Tail Corporation Consolidated
Short-Term Debt	$	112,371	$	--	$	112,371
Long-Term Debt:
Term Loan, LIBOR plus 0.90%, due February 5, 2018			$	--	$	--
3.55% Guaranteed Senior Notes, due December 15, 2026				80,000		80,000
Senior Unsecured Notes 4.63%, due December 1, 2021	$	140,000				140,000
Senior Unsecured Notes 6.15%, Series B, due August 20, 2022		30,000				30,000
Senior Unsecured Notes 6.37%, Series C, due August 20, 2027		42,000				42,000
Senior Unsecured Notes 4.68%, Series A, due February 27, 2029		60,000				60,000
Senior Unsecured Notes 6.47%, Series D, due August 20, 2037		50,000				50,000
Senior Unsecured Notes 5.47%, Series B, due February 27, 2044		90,000				90,000
North Dakota Development Note, 3.95%, due April 1, 2018				27		27
PACE Note, 2.54%, due March 18, 2021				684		684
Total	$	412,000	$	80,711	$	492,711
Less: Current Maturities net of Unamortized Debt Issuance Costs		--		186		186
Unamortized Long-Term Debt Issuance Costs		1,684		461		2,145
Total Long-Term Debt net of Unamortized Debt Issuance Costs	$	410,316	$	80,064	$	490,380
Total Short-Term and Long-Term Debt (with current maturities)	$	522,687	$	80,250	$	602,937