Investments: (Tables)

12 Months Ended

Dec. 31, 2016

Investments:

Summary of activity for available-for-sale securities

		(dollars in thousands)
		Gross Unrealized
2016		Cost		Gains		Losses			Fair Value
Equity	$	237,317	$	51,054	$	(5,041	)	$	283,330
Debt		201,492		1,167		(3,423	)		199,236
Other		3,339		–		(2	)		3,337
Total	$	442,148	$	52,221	$	(8,466	)	$	485,903
		(dollars in thousands)
		Gross Unrealized
2015		Cost		Gains		Losses			Fair Value
Equity	$	230,123	$	37,494	$	(9,635	)	$	257,982
Debt		189,700		1,158		(3,491	)		187,367
Other		5,255		–		(4	)		5,251
Total	$	425,078	$	38,652	$	(13,130	)	$	450,600

Schedule of contractual maturities of debt securities available-for-sale

		(dollars in thousands)
		2016				2015
		Cost		Fair Value		Cost		Fair Value
Due within one year	$	8,292	$	8,268	$	8,559	$	8,612
Due after one year through five years		52,452		52,054		50,018		49,538
Due after five years through ten years		65,657		64,971		56,448		55,880
Due after ten years		75,091		73,943		74,675		73,337
Total	$	201,492	$	199,236	$	189,700	$	187,367

Summary of realized gains and losses and proceeds from sales of securities

		(dollars in thousands)
		2016			2015			2014
Gross realized gains	$	19,934		$	53,453		$	64,437
Gross realized losses		(20,030	)		(18,989	)		(46,258	)
Proceeds from sales		439,540			640,217			438,941

Schedule of investments in associated companies

		(dollars in thousands)
		2016		2015
National Rural Utilities Cooperative Finance Corporation (CFC)	$	24,049	$	24,040
CT Parts, LLC		10,250		11,067
Georgia Transmission Corporation		27,285		25,872
Georgia System Operations Corporation		7,500		7,200
Other		3,699		3,831
Total	$	72,783	$	72,010