Employee Benefit Plans (Other Investment Assets) (Details) (Nonqualified Supplemental Retirement Plans, Deferred Costs, Noncurrent, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 30,068	$ 27,750
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	30,068	27,750
Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12,999	11,952
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	12,999	11,952
United States equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,741	4,546
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	4,741	4,546
Global equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,109	1,798
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	2,109	1,798
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,219	9,454
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	10,219	9,454
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,850	6,344
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	6,850	6,344
Level 1 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Level 1 | United States equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,741	4,546
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	4,741	4,546
Level 1 | Global equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,109	1,798
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	2,109	1,798
Level 1 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,618	16,074
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	17,618	16,074
Level 2 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,399	6,620
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	7,399	6,620
Level 2 | United States equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Level 2 | Global equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Level 2 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,219	9,454
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	10,219	9,454
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,600	5,332
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	5,600	5,332
Level 3 | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,600	5,332
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at beginning of period	5,332	5,069
Unrealized gains relating to instruments held at the reporting date	268	263
Fair value of plan assets at end of period	5,600	5,332
Level 3 | United States equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Level 3 | Global equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	0	0
Level 3 | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Fair value of plan assets at end of period	$ 0	$ 0