Accounts Receivable (Schedule of Accounts Receivable) (Details) (USD $)
In Thousands, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
---|---|---|
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Accounts receivable | $ 222,584 | $ 215,491 |
Allowance for doubtful accounts | (1,154) | (1,627) |
Reserve for cash-basis customers | (2,653) | (2,928) |
Total accounts receivable reserves | (3,807) | (4,555) |
Accounts receivable, net | 218,777 | 210,936 |
Trade Accounts Receivable [Member]
|
||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Accounts receivable | 143,533 | 142,166 |
Unbilled Revenues [Member]
|
||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Accounts receivable | $ 79,051 | $ 73,325 |