Noncontrolling Interests (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Noncontrolling Interests
Revenues	$ 409,995	$ 291,573
Net income attributable to noncontrolling interests	270	44
Tax effect on income recognized	6,207	6,564
Accounts receivable	249,621		268,095
Current liabilities	388,308		420,669
Blythe joint venture
Noncontrolling Interests
Net income attributable to noncontrolling interests	270	44
Cash	4,983		3,565
Accounts receivable	13,715		8,843
Current liabilities	15,130		9,379
Blythe joint venture \| Primary beneficiary
Noncontrolling Interests
Revenues	16,272	1,621
Tax effect on income recognized	0	0
Distributions to noncontrolling interests	0	0
Capital contributions made by noncontrolling interests	$ 0	$ 0

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

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