This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

Name:	us-gaap_AssetsFairValueDisclosureNonrecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on Non-Recurring Basis) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012 Nonrecurring [Member]	Dec. 31, 2012 Level 1 [Member] Nonrecurring [Member]	Dec. 31, 2012 Level 2 [Member] Nonrecurring [Member]	Dec. 31, 2012 Level 3 [Member] Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Lease impairment obligation		$ 7,400,000	$ 0	$ 0	$ 7,400,000
Liabilities, Fair Value Disclosure, Nonrecurring	0
Assets, Fair Value Disclosure, Nonrecurring	$ 0