Nature of Business and Significant Accounting Policies (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash paid for:
Interest	$ 12,922	$ 10,239	$ 1,119
Taxes	$ 88,277	$ 74,333	$ 106,215