Investments and Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2014

Investments, Debt and Equity Securities [Abstract]

Changes in Unrealized Gains and Losses on Available-for-sale Securities

Changes in unrealized gains and losses on available-for-sale securities are included in these financial statements as follows (in thousands):


	Year Ended December 31,
	2014		2013		2012
Changes in unrealized gains and losses on available-for- sale securities, net of tax, recorded in accumulated other comprehensive income (loss)	$	425	$	(456)	$	887

Aggregate Market Value and Unrealized Losses of Investment

The following table shows the number, aggregate market value and unrealized losses (in thousands) of investments with market values that were less than amortized cost as of December 31, 2014. These lower market values are primarily caused by fluctuations in interest rates and credit spreads. Market values are expected to recover to the amortized cost prior to maturity.


	Unrealized Loss < 12 months					Unrealized Loss > 12 months
	Number of investments	Aggregate Market Value		Unrealized Losses		Number of investments	Aggregate Market Value		Unrealized Losses

Government securities	0	$	0	$	0	1	$	8,098	$	(0)
State and municipal bonds	0		0		0	2		1,169		(4)
Corporate Securities	1		446		0	11		2,813		(10)
Other	0		0		0	1		5		(0)

Total	1	$	446	$	0	15	$	12,085	$	(14)

As of December 31, 2013, the number, aggregate market value and unrealized losses (in thousands) of investments with market values that were less than amortized cost were:


	Unrealized Loss < 12 months					Unrealized Loss > 12 months
	Number of investments	Aggregate Market Value		Unrealized Losses		Number of investments	Aggregate Market Value		Unrealized Losses

Government securities	0	$	0	$	0	3	$	23,207	$	(19)
State and municipal bonds	5		7,368		(8)	4		6,559		(20)
Corporate Securities	9		3,031		(2)	60		51,757		(673)
Other	1		1,018		0	2		2,982		(1)

Total	15	$	11,417	$	(10)	69	$	84,505	$	(713)

Schedule of Realized Gains on the Sales of Available-For-Sale Securities

Using the specific identification method, the proceeds and realized gains on the sales of available-for-sale securities were as follows (in thousands):


	Year Ended December 31,

	2014			2013			2012
Proceeds	$	644,378		$	336,741		$	164,410
Realized gains		1,100			727			423
Realized losses		(833	)		(81	)		(78)
Net realized gains included in other comprehensive income (loss) as of the end of the prior year		4			603			285