Benefit Plans Benefit Plans (Detail 12) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Ending	$ 825,774	$ 753,030
Level 3
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Beginning	116,493	93,035
Defined Benefit Plan, Actual Return on Plan Assets Still Held	1,663	4,394
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	2,560	115
Defined Benefit Plan,Purchases, Total	8,799	23,685
Defined Benefit Plan Sales, Total	(32,219)	(3,528)
Foreign Currency Exchange Rate Changes, Plan Assets	2,401	(1,208)
Fair Value of Plan Assets, Ending	99,697	116,493
Other Types of Investments, Multi-Strategy Fund of Hedge Funds
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Ending	74,985	78,650
Other Types of Investments, Multi-Strategy Fund of Hedge Funds | Level 3
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Beginning	78,650	56,398
Defined Benefit Plan, Actual Return on Plan Assets Still Held	1,099	2,704
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	317	112
Defined Benefit Plan,Purchases, Total	8,638	23,534
Defined Benefit Plan Sales, Total	(15,418)	(2,928)
Foreign Currency Exchange Rate Changes, Plan Assets	1,699	(1,170)
Fair Value of Plan Assets, Ending	74,985	78,650
Real Asset Mutual Funds, Commodities
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Ending	57,737	50,656
Real Asset Mutual Funds, Commodities | Level 3
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Beginning	21,816	20,836
Defined Benefit Plan, Actual Return on Plan Assets Still Held	533	987
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Defined Benefit Plan,Purchases, Total	0	0
Defined Benefit Plan Sales, Total	0	0
Foreign Currency Exchange Rate Changes, Plan Assets	637	(7)
Fair Value of Plan Assets, Ending	22,986	21,816
Fixed Income Mutual Funds, Insurance Contracts
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Ending	24,741	16,869
Fixed Income Mutual Funds, Insurance Contracts | Level 3
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Beginning	1,661	1,556
Defined Benefit Plan, Actual Return on Plan Assets Still Held	31	34
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	3	3
Defined Benefit Plan,Purchases, Total	161	151
Defined Benefit Plan Sales, Total	(165)	(37)
Foreign Currency Exchange Rate Changes, Plan Assets	35	(46)
Fair Value of Plan Assets, Ending	1,726	1,661
Other Types of Investments, Convertible Preferred Equity Certificates
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Ending	0	14,366
Other Types of Investments, Convertible Preferred Equity Certificates | Level 3
Rollforward of Activity for Level 3 Asset Categories [Roll Forward]
Fair Value of Plan Assets, Beginning	14,366	14,245
Defined Benefit Plan, Actual Return on Plan Assets Still Held	0	669
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	2,240	0
Defined Benefit Plan,Purchases, Total	0	0
Defined Benefit Plan Sales, Total	(16,636)	(563)
Foreign Currency Exchange Rate Changes, Plan Assets	30	15
Fair Value of Plan Assets, Ending	$ 0	$ 14,366