Employee Benefit Plans (Fair Value Measurement Levels For Qualified Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Cash	$ 611,382		$ 537,050
Short-term investments, which approximates fair value	10,590	[1]	3,343	[1]
Multi-strategy equity fund, fair value	10,765	[2]	9,092	[2]
Private equity limited partnerships	9,156	[3]	5,524	[3]
Total	152,446		114,807
Percent of fixed income funds in US securities	50.00%		50.00%
Percent of fixed income funds in international securities	50.00%		50.00%
Percent of equities mutual funds in US equities	90.00%		75.00%
Percent of equities mutual funds in international equities	10.00%		25.00%
Cash Managed By Employee Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Mutual funds, fair value	24,630	[4]	33,783	[4]
Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Mutual funds, fair value	97,305	[5]	63,065	[6]
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Short-term investments, which approximates fair value	10,590	[1]	3,343	[1]
Total	132,525		100,191
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Cash Managed By Employee Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Mutual funds, fair value	24,630	[4]	33,783	[4]
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Mutual funds, fair value	97,305	[5]	63,065	[6]
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Short-term investments, which approximates fair value		[1]		[1]
Multi-strategy equity fund, fair value		[2]		[2]
Private equity limited partnerships		[3]		[3]
Total
Significant Other Observable Inputs (Level 2) [Member] | Cash Managed By Employee Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash
Significant Other Observable Inputs (Level 2) [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Mutual funds, fair value		[4]		[4]
Significant Other Observable Inputs (Level 2) [Member] | Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Mutual funds, fair value		[5]		[6]
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Multi-strategy equity fund, fair value	10,765	[2]	9,092	[2]
Private equity limited partnerships	9,156	[3]	5,524	[3]
Total	19,921		14,616
Significant Unobservable Inputs (Level 3) [Member] | Cash Managed By Employee Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash

[1] This category includes high quality, short-term money market instruments, which are issued and payable in U.S. dollars.

[2] This category consists of a privately held fund of U.S. and international equity funds and may include currency hedges for the foreign funds. The fair value is provided by the external investment manager.

[3] This category consists of private equity limited partnerships.

[4] This category includes fixed income funds, which invest in investment grade securities of corporations, governments and government agencies with approximately 50% in U.S. securities and 50% in international securities.

[5] This category includes funds, which invest in small, mid and multi-cap equity securities including common stocks, securities convertible into common stock and securities with common stock characteristics, such as rights and warrants, with approximately 90% in U.S. equities and 10% in international equities.

[6] This category includes funds, which invest in small, mid and multi-cap equity securities including common stocks, securities convertible into common stock and securities with common stock characteristics, such as rights and warrants, with approximately 75% in U.S. equities and 25% in international equities.