Fair Value Measurements (Additional Disclosures) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jun. 14, 2012	Feb. 04, 2011	Jan. 06, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Common share price, per share		$ 9.96		$ 9.53	$ 6.63	$ 4.81
Impairment of assets	$ 0	$ 0
Impairment of long-lived assets	0	0	8,898,000
Impairment loss relating to other intangible assets	0	0	400,000
Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value adjustments, net	$ (2,649,000)	$ (9,571,000)