Marketable Securities - Unrestricted Marketable Securities - Unrestricted (Schedule of Unrealized Losses) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Number In Loss Position	1
Less than twelve months - fair values	$ 12,460
Less than twelve months - unrealized losses	(229)
12 months or greater - fair value	0
12 months or greater - unrealized losses	0
Total Fair Value	12,460
Total Unrealized Losses	(229)
Mutual Funds
Schedule of Available-for-sale Securities [Line Items]
Number In Loss Position	1
Less than twelve months - fair values	12,460
Less than twelve months - unrealized losses	(229)
12 months or greater - fair value	0
12 months or greater - unrealized losses	0
Total Fair Value	12,460
Total Unrealized Losses	$ (229)