Pension Plan Contributions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Qualified Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Estimated future employer contributions in next fiscal year	$ 10,000	[1]
Contributions by employer	10,000		10,000
Supplemental Employee Retirement Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Estimated future employer contributions in next fiscal year	531
Contributions by employer	$ 819		$ 2,291

[1] As of the date of this report, the Company has already contributed this $10.0 million to the qualified pension plan; no further contributions are expected to be made in 2015.