Income Taxes Unrecognized Benefit (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions		$ 4,492,000	$ 0
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	9,438,000	4,083,000	4,481,000
Current period tax positions		1,958,000	582,000
Lapse of statute of limitations	(1,200,000)	(1,095,000)	(980,000)
Balance at end of year		9,438,000	4,083,000	4,481,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound		8,000,000
Significant Change In Unrecognized Tax Benefits Accrued Interest And Penalties		5,700,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate			3,600,000
Unrecognized Tax Benefits, Interest on Income Taxes Expense		563,000	25,000	86,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued			$ 1,400,000	$ 819,000