Defined Benefit Plans Annual Disclosures (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 0	$ 4,389		$ 5,230
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation	3,592	4,436
Service cost	0	0		53
Interest cost	84	207		216
Actuarial loss (gain)	(2)	(93)
Benefits paid	(3,791)	(48)
Curtailments	0	0
Lump sum settlement	117	910
Effect of change in currency conversion	0	0
Benefit Obligation	0	3,592		4,436
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets	4,389	5,230
Actual return on plan assets	306	153
Employer contributions	0	1
Benefits paid	(3,791)	(956)
Transfer to qualified replacement plan	(874)	0
Expenses paid from the plan	(30)	(39)
Fair Value of Plan Assets	0	4,389		5,230
Funded balance at end of year	0	797
Pension and Other Postretirement Defined Benefit Plans, Liabilities [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities	0	797
Accumulated Benefit Obligation	0	3,592
Components of net periodic benefit cost included in employee compensation and benefits
Service cost	0	0		53
Interest cost	84	207		216
Expected return on plan assets	(299)	(251)		(235)
Amortization of (loss) / gain	(205)	0		0
Amortization of prior service cost	0	21		20
Effect of settlement	0	(95)		(95)
Net periodic benefit cost	(420)	(118)		(41)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Gain (Loss)	344	137		(557)
Effect of Curtailment	0	(360)		59
Effect of Settlement	0	0		98
Amortization of Loss (Gain)	0	0		0
Amortization of prior service cost included in net periodic pension cost	0	23		23
Total recognized in other comprehensive income (loss)	344	(246)		(423)
Defined Benefit Plan, Amounts Recognized in Net Periodic Benefit Cost and Other Comprehensive Loss (Income)	(76)	(364)		(464)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]
Net Gains (Losses)	0	344		479
Prior Service Cost	0	0		(381)
Effect of change in currency conversion	0	0		0
Total recognized in accumulated other comprehensive income (loss)	0	344		98
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior Service Cost	0	0		19
Net Gains (Losses)	0	0		0
Cash Balance Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets	6.00%	6.00%		6.00%
Fair Value of Plan Assets		4,389
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets	4,389
Fair Value of Plan Assets		4,389
Cash Balance Plan | Ramius Multi-Strategy Fund Ltd
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		390	[1]
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets		390	[1]
Cash Balance Plan | Merger Fund
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		2,279
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets		2,279
Cash Balance Plan | Orchard Square Partners Credit Fund Ltd
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		1,640	[2]
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets		1,640	[2]
Cash Balance Plan | External Mutual Funds Total Return
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		7	[3]
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets		7	[3]
Cash Balance Plan | External Mutual Funds Real Return
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		34	[4]
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets		34	[4]
Cash Balance Plan | External Mutual Funds Conservative
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets		39	[5]
Defined Benefit Plan, Change in Plan Assets [Roll Forward]
Fair Value of Plan Assets		$ 39	[5]

[1] Ramius Multi-Strategy Fund Ltd invests substantially all of its capital through a "master feeder" structure in Ramius Intermediate Fund, L.P. which invests in funds that employ a variety of diversified, non-directional investment strategies that seek to achieve, over the long term, a target return with low volatility.

[2] Orchard Square Partners Credit Fund Ltd invests substantially all of its capital through a "master-feeder" structure in Orchard Square Partners Credit Intermediate Fund, LP which invests in a fund whose objective is to seek to achieve superior returns.

[3] External Mutual Funds—Total Return's main objective is to achieve maximum total return by investing assets in a diversified portfolio of fixed income instruments of varying maturities which may be represented by derivatives.

[4] External Mutual Funds—Real Return's main objective is to seek to achieve maximum total return after inflation consistent with preservation of real capital and prudent investment management.

[5] External Mutual Funds—Conservative's main objective is to seek to achieve a high level of current income with some consideration given to the growth of capital by investing in fixed-income securities.