Income Taxes (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of year	$ 29,200,000	$ 30,949,000	$ 8,297,000
Increases related to current year tax positions	7,220,000	1,225,000	2,339,000
Increases related to prior year tax positions	1,559,000	4,192,000	1,561,000
Decreases related to prior year tax positions	(343,000)	(4,608,000)	(11,000)
Acquisitions	0	0	25,716,000
Lapse of statute of limitations	(1,887,000)	(2,558,000)	(6,953,000)
Settlements	(606,000)	0	0
Balance, end of year	35,143,000	29,200,000	30,949,000
Unrecognized tax benefits which would affect the effective tax rate if recognized	22,800,000
Accrued interest and penalties	2,300,000
Accrued interest and penalties net of federal and state benefits	$ 2,200,000