Stock-Based Compensation and Equity (Narratives) (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended							1 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Officers WPCI	Sep. 30, 2014 CPA: 16 - Global	Mar. 31, 2014 CPA: 16 - Global	Jan. 31, 2014 CPA: 16 - Global	Sep. 30, 2014 CPA: 16 - Global Measurement period adjustment	Jun. 30, 2014 CPA: 16 - Global Measurement period adjustment	Oct. 31, 2014 Subsequent Event Revolving Credit Facility	Sep. 30, 2014 Additional Paid-in Capital
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense		$ 7,979,000	$ 7,852,000	$ 22,979,000	$ 25,430,000
Tax benefit from stock based compensation expense			0	17,300,000	16,000,000
Risk free interest rate				0.65%
Fair value assumptions expected volatility rate				25.89%
Fair value assumptions expected volatility rate peer index				21.77%
Fair value assumptions expected dividend rate				0.00%
Fair value of vested stock				24,700,000
Deferred compensation, shares	889,863	889,863		889,863
Deferred compensation obligation	30,624,000	30,624,000		30,624,000		11,354,000
Unrecognized stock based compensation expense	31,400,000	31,400,000		31,400,000
Weighted-average remaining term				1 year 8 months 1 day
Options exercised in period	600,000			93,745
Options exercised during the period, aggregate intrinsic value				3,200,000
Fair value of noncontrolling interests acquired								278,187,000	278,829,000	278,187,000	(642,000)	600,000
Stock options outstanding	525,035	525,035		525,035
Stock options exercisable	453,324	453,324		453,324
Public Offering
Share issued in public offering, shares	4,600,000
Common stock, per share value	$ 0.001	$ 0.001		$ 0.001		$ 0.001
Share price	$ 64.00	$ 64.00		$ 64.00
Proceeds from issuance of shares in public offering				282,586,000	0									282,157,000
Distributions Declared
Distributions declared		$ 0.940	$ 0.860	$ 2.735	$ 2.520	$ 3.39
Dividend payable date				Oct. 15, 2014
Redeemable Noncontrolling Interest
Minority interest ownership interest							7.70%
Redeemable noncontrolling interest	6,346,000	6,346,000		6,346,000		7,436,000
Repayment of debt													$ 225,800,000