Employee Benefit Plans (Cash-Equivalent Stock Awards) (Details) (USD $) In Thousands, except Share data, unless otherwise specified				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Cash Equivalent Stock Awards [Member]	Dec. 31, 2013 Cash Equivalent Stock Awards Rsus [Member]	Dec. 31, 2013 Cash Equivalent Stock Awards Performance Based [Member]
Activity:
Outstanding, beginning of year				610,537	407,504
Granted, shares				337,002	98,279
Additional awards granted due to achievement of performance criteria, shares					4,722
Forfeited, shares				(51,223)	(4,396)
Fully vested, shares				(213,288)	(162,122)
Outstanding, end of year				683,028	343,987
Weighted average grant date fair value:
Outstanding, beginning of year - weighted average grant date fair value				$ 59.86	$ 57.26
Granted - weighted average grant date fair value				$ 87.77	$ 87.73
Additional awards granted due to achievement of performance criteria - weighted average grant date fair value					$ 46.05
Forfeited - weighted average grant date fair value				$ (69.40)	$ (63.37)
Vested - weighted average grant date fair value				$ (56.08)	$ (46.05)
Outstanding, end of year - weighted average grant date fair value				$ 74.10	$ 71.02
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Accounts payable and accrued liabilities	$ 170,225	$ 145,628	$ 54,358
Vesting period				4 years	3 years