Long-Term Incentive Plan (Details Textual) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Long-Term Incentive Plan (Textual) [Abstract]
Shares of common stock reserved for future grants under the plan	2,187	2,975	3,996
Compensation cost charged against income from continuing operations	$ 8,009	$ 5,579	$ 5,842
Total income tax benefit for share-based compensation arrangements	2,947	2,067	2,153
Granted	0	0	609
Weighted-average grant-date fair value of the RSUs granted			$ 4.78
Options granted expiration period	10 years
Maximum [Member]
Long-Term Incentive Plan (Textual) [Abstract]
Options granted vesting period	3 years
Minimum [Member]
Long-Term Incentive Plan (Textual) [Abstract]
Options granted vesting period	1 year
Restricted Stock Units (RSUs) [Member]
Long-Term Incentive Plan (Textual) [Abstract]
Unrecognized compensation cost, weighted average recognition period	1 year 2 months 12 days
Percentage of Series A Common Stock for redemption of RSUs	60.00%
Percentage of cash for redemption of RSUs	40.00%
Weighted-average grant-date fair value of the RSUs granted	$ 7.17	$ 7.87	$ 7.20
RSUs were converted into shares of stock	545	726	891
RSUs paid in share-based liabilities	1,188	2,268	2,447
Unrecognized compensation cost related to non-vested options	87
Unrecognized compensation cost related to non-vested options RSUs	$ 5,978
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Long-Term Incentive Plan (Textual) [Abstract]
Stock awards other than options vesting period		3 years
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Long-Term Incentive Plan (Textual) [Abstract]
Stock awards other than options vesting period	1 year
Stock Options [Member]
Long-Term Incentive Plan (Textual) [Abstract]
Unrecognized compensation cost, weighted average recognition period	2 months 12 days
Rolling Average Period Used to Determine Expected Life of Options	10 years