Investments - Narrative (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 8,872		$ 34,214
Cost Basis	9,007	[1]	34,202	[1]
Pre-Refunded And Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	0		14,877
Cost Basis	0	[1]	15,047	[1]
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,652		1,779
Cost Basis	1,652	[1]	1,779	[1]
Other Investment [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	362		362
Cost Basis	362	[1]	362	[1]
Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 900		$ 800

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