Long-Term Debt (Senior Convertible Notes) (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended			0 Months Ended	1 Months Ended		12 Months Ended	0 Months Ended
	Apr. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 28, 2012 Director [Member] Convertible Debt [Member] Senior Convertible Notes [Member]	Apr. 30, 2013 Director [Member] Convertible Debt [Member] Senior Convertible Notes [Member]	Nov. 30, 2011 Director [Member] Convertible Debt [Member] Senior Convertible Notes [Member]	Dec. 31, 2012 Director [Member] Convertible Debt [Member] Senior Convertible Notes [Member]	May 28, 2012 Minimum [Member] Director [Member] Convertible Debt [Member] Senior Convertible Notes [Member]	May 28, 2012 Maximum [Member] Director [Member] Convertible Debt [Member] Senior Convertible Notes [Member]
Debt Instrument [Line Items]
Long-term debt due to related party		$ 0	$ 200,000,000				$ 200,000,000
Proceeds from issuance of debt, net of issuance costs		490,586,000	(295,000)	198,060,000			197,800,000
Debt issuance costs, net							2,200,000
Payment of debt issuance costs								$ 300,000
Weighted average price of common stock					$ 111.54
Trading days prior to conversion date required for conversion									50 days	65 days
Common stock, shares issued	2,300,000					2,300,000
Common stock conversion ratio						11.6553
Fair value at conversion						$ 216.99