Employee Benefit Plans (Fair Value of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 27	$ 67,542	$ 193,457
Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27	67,542
Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Pension Benefits | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27	67,542
Pension Benefits | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	27	67,542
Pension Benefits | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,369	10,693	$ 55,459
Postretirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,835	6,426
Postretirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,534	4,267
Postretirement Benefits | United States equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,185	4,715
Postretirement Benefits | United States equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,185	4,715
Postretirement Benefits | United States equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits | Global equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,650	1,711
Postretirement Benefits | Global equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,650	1,711
Postretirement Benefits | Global equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,534	4,267
Postretirement Benefits | Fixed income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Postretirement Benefits | Fixed income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4,534	$ 4,267