Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation costs	$ 7,409	$ 4,191	$ 14,326	$ 10,222
Less amount capitalized into qualifying real estate projects	(1,422)	(555)	(3,084)	(2,620)
Amount charged to operating expenses	5,987	3,636	11,242	7,602
Depreciation expense on capitalized stock-based compensation	226	189	452	447
Total stock-based compensation expense	6,213	3,825	11,694	8,049
Deferred income tax benefit	2,438	1,455	4,511	3,021
Stock option costs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation costs	12	523	665	1,979
Restricted stock costs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation costs	3,597	2,579	8,601	6,303
Performance share costs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation costs	$ 3,800	$ 1,089	$ 5,060	$ 1,940