Nature Of Operations And Basis Of Presentation (Intercompany Transactions) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Accounts receivable for NPL services	$ 121,865	$ 147,605
NPL Construction Co [Member]
Accounts receivable for NPL services	$ 9,644	$ 8,111

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 3
-Subparagraph a(1)
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 4
-Article 5

Name:	us-gaap_AccountsReceivableNetCurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant