Short- and Long-Term Investments and Investments on Deposit for Licensure (Tables)

9 Months Ended

Sep. 30, 2012

Investments, Debt and Equity Securities [Abstract]

Reconciliation schedule of available-for-sale securities from cost basis to fair value

The amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value for available-for-sale short- and long-term investments and investments on deposit for licensure held at September 30, 2012 were as follows (dollars in thousands):

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
Certificates of deposit	$	13,024	$	—	$	—	$	13,024
Commercial paper	61,301		132		—		61,433
Corporate bonds	594,446		5,086		27		599,505
Debt securities of government sponsored entities	145,538		625		6		146,157
Equity index funds	66,562		6,217		104		72,675
Money market funds	87,752		—		—		87,752
Municipal bonds	478,955		20,123		355		498,723
U.S. Treasury securities	14,746		64		—		14,810
Total	$	1,462,324	$	32,247	$	492	$	1,494,079

The amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value for available-for-sale short- and long-term investments and investments on deposit for licensure held at December 31, 2011 were as follows (dollars in thousands):

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
Certificates of deposit	$	118,081	$	13	$	—	$	118,094
Commercial paper	172,657		2		95		172,564
Corporate bonds	565,382		2,852		1,510		566,724
Debt securities of government sponsored entities	289,901		742		100		290,543
Equity index funds	40,146		1,355		658		40,843
Money market funds	15,067		—		—		15,067
Municipal bonds	394,599		16,978		1,000		410,577
U.S. Treasury securities	26,045		80		1		26,124
Total	$	1,621,878	$	22,022	$	3,364	$	1,640,536

Schedule of amortized cost and fair value of available-for-sale debt securities by contractual maturity

The amortized cost and fair value of investments in debt securities, by contractual maturity, for available-for-sale short- and long-term investments and investments on deposit for licensure held at September 30, 2012 were as follows (dollars in thousands):

	Amortized Cost		Fair Value
Maturing within one year	$	505,042	$	506,170
Maturing between one year and five years	570,644		578,694
Maturing between five years and ten years	238,334		252,493
Maturing in greater than ten years	81,742		84,047
Total	$	1,395,762	$	1,421,404

Schedule of available-for-sale securities with unrealized losses not deemed to be other-than-temporarily impaired

The following tables show the fair value of the Company’s available-for-sale investments with unrealized losses that are not deemed to be other-than-temporarily impaired at September 30, 2012 and December 31, 2011. Investments are aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (dollars in thousands):

	Less than 12 Months					12 Months or Greater
	Fair Value		Gross Unrealized Holding Losses		Total Number of Securities	Fair Value		Gross Unrealized Holding Losses		Total Number of Securities
September 30, 2012:
Corporate bonds	$	21,179	$	27	35	$	—	$	—	—
Debt securities of government sponsored entities	5,625		6		5	—		—		—
Equity index funds	4,646		104		2	—		—		—
Municipal bonds	36,852		86		16	2,556		269		1
Total temporarily impaired securities	$	68,302	$	223	58	$	2,556	$	269	1
	Less than 12 Months					12 Months or Greater
	Fair Value		Gross Unrealized Holding Losses		Total Number of Securities	Fair Value		Gross Unrealized Holding Losses		Total Number of Securities
December 31, 2011:
Commercial paper	$	149,074	$	95	12	$	—	$	—	—
Corporate bonds	185,231		1,498		98	8,989		12		1
Debt securities of government sponsored entities	103,766		100		28	—		—		—
Equity index funds	17,021		658		5	—		—		—
Municipal bonds	5,129		1		1	11,551		999		3
U.S. Treasury securities	12,025		1		3	—		—		—
Total temporarily impaired securities	$	472,246	$	2,353	147	$	20,540	$	1,011	4

Realized gains and losses from the sale or call of available-for-sale securities

Realized gains and losses for the three and nine months ended September 30, 2012 and 2011 were as follows (dollars in thousands):

	Three Months Ended September 30,					Nine Months Ended September 30,
	2012			2011		2012			2011
Gross realized gains	$	236		$	84	$	2,758		$	134
Gross realized losses	(8		)	—		(60		)	(9		)
Net realized gains	$	228		$	84	$	2,698		$	125