Income Taxes - Unrecognized Tax Benefits Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Unrecognized Tax Benefits Reconciliation
Balance at beginning of year	$ 46,980	$ 63,498	$ 66,110
Additions based on tax positions taken during a prior period	22,170	448	10,850
Reductions based on tax positions taken during a prior period	(3,684)	(11,824)	(2,389)
Additions based on tax positions taken during the current period	7,593	8,014	7,602
Reductions related to settlement of tax matters	(24,450)	(8,288)	(12,879)
Reductions related to a lapse of applicable statute of limitations	(2,622)	(4,868)	(5,796)
Balance at end of year	45,987	46,980	63,498
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 10,637	$ 10,599