Income Taxes (Tax Expiration) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	$ 110,285
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	18,216
Year of Expiration 2018 Through 2024 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	0
Year of Expiration 2018 Through 2024 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	0
Year of Expiration 2027 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	6,256
Year of Expiration 2027 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	840
Year of Expiration 2028 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	40,193
Year of Expiration 2028 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	2,108
Year of Expiration 2029 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	9,742
Year of Expiration 2029 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	1,148
Year of Expiration 2030 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	5,281
Year of Expiration 2030 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	1,162
Year of Expiration 2031 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	3,292
Year of Expiration 2031 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	3,097
Year of Expiration 2032 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	2,917
Year of Expiration 2032 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	3,622
Year of Expiration 2033 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	38,155
Year of Expiration 2033 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	3,239
Year of Expiration 2034 [Member] | General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	4,449
Year of Expiration 2034 [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax carryforwards	$ 3,000