Investments - Schedule Of Amortized Costs And Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 9,007	[1]	$ 34,202	[1]
Fair Value	8,872		34,214
Accumulated Unrealized Gains Losses On Available For Sale Securities Before Tax	(135)		12
Pre-Refunded And Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	0	[1]	15,047	[1]
Fair Value	0		14,877
Accumulated Unrealized Gains Losses On Available For Sale Securities Before Tax	0		(170)
Net unrealized gain (loss) in AOCI			100
Short-Term Bond Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	6,993	[1]	17,014
Fair Value	6,858		17,196
Accumulated Unrealized Gains Losses On Available For Sale Securities Before Tax	(135)		182
Net unrealized gain (loss) in AOCI	100		100
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	1,652	[1]	1,779	[1]
Fair Value	1,652		1,779
Net unrealized gain (loss) in AOCI	0		0
Other Investment [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	362	[1]	362	[1]
Fair Value	362		362
Net unrealized gain (loss) in AOCI	$ 0		$ 0

[1] The cost basis represents the actual amount paid less any permanent impairment recorded on that asset.