Stock-Based Compensation Plans - Schedule of Outstanding Options into Two Ranges, Based on Exercise Prices (Detail) - Jun. 30, 2015 - $ / shares shares in Thousands	Total
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices remaining contractual life, outstanding	7 years
Range of exercise prices shares, outstanding	138
Range of exercise prices weighted average exercise price, outstanding	$ 49
Range of exercise prices shares, exercisable	77
Options Exercisable, Weighted Avg. Exercise Price	$ 45
Outstanding Options with Range Based Exercise Prices Set One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	37.04
Exercise price range, upper range limit	$ 46.93
Range of exercise prices remaining contractual life, outstanding	6 years 3 months 18 days
Range of exercise prices shares, outstanding	80
Range of exercise prices weighted average exercise price, outstanding	$ 44
Range of exercise prices shares, exercisable	56
Options Exercisable, Weighted Avg. Exercise Price	$ 43
Outstanding Options with Range Based Exercise Prices Set Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	48.00
Exercise price range, upper range limit	$ 60.40
Range of exercise prices remaining contractual life, outstanding	8 years
Range of exercise prices shares, outstanding	58
Range of exercise prices weighted average exercise price, outstanding	$ 55
Range of exercise prices shares, exercisable	21
Options Exercisable, Weighted Avg. Exercise Price	$ 50

POST APARTMENT HOMES LP 10-Q