Income Taxes Tax Contingency (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, January 1		$ 4,570	$ 6,017	$ 4,246
Changes for tax positions of prior years		410	173	18
Increases for tax positions related to the current year	1,900	0	2,062	2,563
Settlements and lapsing of statutes of limitations		565	3,682	774
Balance, December 31		4,415	4,570	6,017
Scenario, Forecast [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Settlements and lapsing of statutes of limitations		$ 2,100