Available-for-sale Securities (Details) - Long-term Debt, Type [Domain] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Document Period End Date	Jun. 30, 2015
Available-for-sale Securities, Amortized Cost Basis	$ 7,930
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	1
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(31)
Available-for-sale Securities, Equity & Debt Maturities, Rolling Year One Through Three, Fair Value	4,171
Available-for-sale Securities, Equity & Debt Maturities, Rolling After Year Three, Fair Value	1,521
Available-for-sale Securities, Equity & Debt Maturities, Next Rolling Twelve Months, Fair Value	2,208
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Equity Maturities, Next Rolling Twelve Months, Fair Value	1,751
Available-for-sale Securities, Amortized Cost Basis	1,750
Available-for-sale Equity Securities, Gross Unrealized Loss	1
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax	0
Available-for-sale Securities	1,751
Available-for-sale Securities, Equity Maturities, Rolling Year One Through Three, Fair Value	0
Available-for-sale Securities, Equity Maturities, Rolling After Year Three, Fair Value	0
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	0
Available-for-sale Securities	7,900
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	6,180
Available-for-sale Securities	6,149
Available-for-sale Securities, Debt Maturities, Rolling Year One Through Three, Fair Value	4,171
Available-for-sale Securities, Debt Maturities, Rolling After Year Three, Fair Value	1,521
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value	457
Available-for-sale Debt Securities, Gross Unrealized Loss	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	$ (31)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		$ 14,350
Available-for-sale Equity Securities, Gross Unrealized Loss		914
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax		0
Available-for-sale Securities		$ 15,264