Derivative Financial Instruments (Details 2) (Designated as cash flow hedging instruments, USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Interest rate cap
Entity's derivative instruments within the consolidated balance sheets
Asset derivatives	$ 1
Interest rate cap | Other current assets
Entity's derivative instruments within the consolidated balance sheets
Asset derivatives	1
Interest rate swaps
Entity's derivative instruments within the consolidated balance sheets
Liability derivatives	3,080
Interest rate swaps | Other current liabilities
Entity's derivative instruments within the consolidated balance sheets
Liability derivatives	$ 3,100