Financial Instruments (Contractual Maturities) (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financial Instruments Contractual Maturities Details 3
Due within one year, amortized cost	$ 115,325	$ 103,280
Due after one year through five years, amortized cost	7,011	26,005
Due after five years through ten years, amortized cost	0	0
Due within one year, fair value	115,305	103,266
Due after one year through five years, fair value	7,011	26,004
Due after five years through ten years, fair value	0	0
Total debt securities, amortized cost	122,336	129,285
Total debt securities, fair value	$ 144,806	$ 155,081