Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended		3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014 Internal Revenue Service (IRS)	Sep. 30, 2012 Internal Revenue Service (IRS)	Mar. 31, 2014 Colorado	Mar. 31, 2014 Minnesota	Mar. 31, 2014 Texas	Mar. 31, 2014 Wisconsin
Tax Audits [Abstract]
Number Of Years Of Tax Loss Carryback Period	2
Tax Adjustments, Settlements, and Unusual Provisions		$ (12,000,000)	$ (15,000,000)	$ 10,000,000
Year(s) no longer subject to audit as statute of limitations has expired				2008
Earliest year subject to examination				2009		2009	2009	2009	2009
Year(s) under examination					2010 and 2011
Tax year(s) for which income tax examination has been completed									2009 through 2011
Unrecognized Tax Benefits [Abstract]
Unrecognized tax benefit — Permanent tax positions	7,400,000	12,900,000
Unrecognized tax benefit — Temporary tax positions	27,800,000	28,300,000
Total unrecognized tax benefit	35,200,000	41,200,000
NOL and tax credit carryforwards	(23,000,000)	(27,100,000)
Upper bound of decrease in unrecognized tax benefit that is reasonably possible	(8,000,000)
Amounts accrued for penalties related to unrecognized tax benefits	$ 0	$ 0