Debt (Schedule of Long-term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term Debt	$ 703,299	$ 502,513
Long-term Debt, Current Maturities	(202,166)	(2,847)
Long-term Debt, Excluding Current Maturities	501,133	499,666
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	1,711	2,927
Senior Notes [Member] | Senior Notes, Issued [Member]
Debt Instrument [Line Items]
Long-term Debt	621,588	419,586
Revolving Credit Facility [Member] | Senior secured revolving credit facility [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 80,000	$ 80,000